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I am currently renovating my new first home and I need to do this to my entire house (external solid walls) Just wondering, did you need to get Building regulations approval to do this ? I'm a little confused where I stand with this. I have to do attic, walls and insulate under the raised floor.
I wonder if you have secured/ painted external walls. To be honest, I wouldn't go for that internal installation. Better would be external for longer run.
I built a two storey extension as a granny annex in 2003 using 40mm laminate plasterboard dob and dabbed onto 9" solid block work. I recently put new doors and windows in and uncovered a lot of the original wall surface. Not a hint of mould or condensation. External walls are rendered pebbledash. I am now doing the same to the main house external walls as i replace the old leaded light windows. If you try and consider all the issues you come to the conclusion its not worth it bearing in mind the cost and no one can get give a definite way to do it. however I need to be warmer as i get older in the winter. This time I am using adhesive foam which almost removes any gap behind the insulation as it needs perfect contact (keep pressure applied for half-hour plus across the whole board with temporary wood support and of course mechanical fixings). We do intend to open windows as much as possible to reduce humidity issues. in 10 years time I'll let you know if it worked!
Amazing to find a builder who actually does understand and considers how to refurb properly and follows or improves on building regs. If only every builder did this.
Eager to see how you achieve this. I am going through a renovation myself and we have decided against internal wall insulation due to several factors. and will therefore try to attempt external insulation in the future. I spent ages reading about how to insulate, and even airtightness, and too many approaches out there to say the least. It was too confusing and tradespeople did not help.
Interesting video Charlie. Not to be only pointing out issues but I see two potential problems with this arrangement. Firstly there are many unventilated cavity spaces right where the dewpoint position is (internal face of the brickwork wall), surely that is perfect conditions for mould. Secondly, with the batten fixed directly to the brickwall they will act as cold bridges, a studded frame build independently say 20mm off the brickwork would have avoid the cold bridge, or even a "warm" batten with 25mm insulation fixed behind the batten. Regardless an interesting subject where it is near impossible to satisfy all requiments!
Positive ventilation unit pushing air into the cavity space if its a continuous maze gap with trickle vent exits? would that cause any issues with the inner shell?
Great video Charlie, I've been getting involved in external and some internal insulation, I have solid walls and have researched this complicated subject, I have used alutrix vapour barrier and a combination of foam fixing and insulated plasterboard. you can end up chasing cold bridges until the cows come home . Somewhere the vapour barrier has to be breached. As you rightly say, ventilation is essential as moisture will build up eventually. Interestingly I ripped down 4mm conti board pinned to batten on my dining room walls and found the external walls bone dry. Unluckily my lead roof laid 20 years ago on a warm roof where no barrier was installed erupted and dissolved to white dust. You live and learn.
I will be doing this very shortly in my two front rooms. I have decided use PIR straight onto the brick wall, batten a frame in front of it and screw battens to ceiling and floor joists. This way there is no compromise in the insulation. Socks can go in the void behind the stud wall.
There are a number of internal wall insulation options that are breathable which is the best option as you get you u-value. These include but not limited to wood fiber insulation and lime render with cork or pumus stone in it put on at about 50m thick. (A friend did the latter on his listed cottage and it's amazingly warm)
@@inh415 breathability and air-tightness are two different things. Materials like wood fibre can help to prevent moisture buildup in walls by absorbing any condensation at the cold surface (assuming good contact with a breathable adhesive like a lime mix). The moisture can then be wicked back through the insulation, and when the internal humidity drops breath out into the room again. Air tightness on the other hand prevents penetration of air from outside. Wood fibre insulation, whilst not completely air tight, does obstruct airflow, and you can get vapour-open air-tight materials, both as membranes and as paint-on treatments. And intelligent valour membranes can be used to prevent/reduce vapour penetration into the wall from the room, whilst still allowing vapour to breath out into the room (usually at a certain relative humidity and temperature range).
@@DevAnubis Yep, i'm looking at this option as well, wood fibre boards from STEICO. It fits in with the "design philosphy" (if you can call it that) of an old solid brick walled house. Back in the day they didnt have the means to stop moisture at any point (sandstone block foundation) and just let it come and go. And they ran direct wood-fired stoves which kill moisture so fast you wish you had more lol. Covering up these walls from any side with anything that stops water is asking for trouble. The wood fibre board solution sounds almost too good to be true as the installation looks fairly simple and doesnt require several layers of whatnot.
Woodfibre insulation fully bonded to the wall with lime plaster over or Diathonite insulated plaster would have been the best option. Standard best practice is to not leave a cavity next to the wall as you will get mould growth just like you did before. It is almost impossible to prevent air ingress into that cavity. You also need to remember to insulate between the joists in the inter floor void next to the wall having parge coated first around the joists to prevent air ingress.
Hmm, yet perhaps to reduce service penetrations you could perform your insulation then have a horizontally battened service cavity with airtightness layer behind traditional plasterboard. This means religiously taping that barrier behind each socket box and penetration before mounting the plasterboard.
Better still simply tape the airtight barrier to the Lime insulation, then attach the electrics taking care to seal around the screws. The same dedication would have to be taken for the screws mounting the plasterboard battens. Then attach the boards..
Good stuff. Having looked into internal insulation it's clear that it's a murky area with unclear best practices. Props for trying to tackle the issue and bring clarity on different options
Agreed - I've been upgrading my home, which has a cavity wall that the previous owners insulated at some point. Trying to get any consistent information on how to boost the insulation is nigh impossible. I went with a dot-dab insulation approach like I saw on this channel before and it has been extremely effective for me in one room, now considering whether to do likewise in other rooms, it looks like there might be ways to up the game.
@Alex Barlow dot and dab is fine for most walls as long as there is no shelving or units built there like a kitchen etc. It becomes a pain in the backside though if you decide to start putting up shelves or units after. If its like 50mm insulation or higher. We went with battoning the walls like Charlie here and used two 2x2 stacked on top of each other which allowed us to fit 80mm insulation in between it with a few mm gap for air. We're very happy with it and it's very warm now, even during the last winter. But we also upgraded all the windows to triple glazed from Poland as well. Definitely recommend but either way, insulating is such a great investment. We insulated the whole lot for about £6000 and got the windows for £3500. All the work done ourselves.
I would use Steico's system of applying wood fiber board to a masonry surface and then finish with either a vapor permeable wallboard or a lime plaster which is also vapor permeable. I would then finish with a vapor permeable paint. You are relying on a cold air cavity to control moisture which will over time probably fail. You are also not allowing the walls to dry out causing them to deteriorate over time. The walls were made to breathe, you have to let them.
Charlie says its a '2 brick course with no cavity' - we dont know if its a lime mortar pointing(but he seems to allude to that with the proposed lime insulation solution eval). If he currently has a "mix and match" lime and cement mortar pointing(which is typically of older houses with a mix of more recent renovations). IMO Even with a lime internal plaster composite integrated insulation layer(no gap) it may not resolve the damp penetration patches and cold spots due to any prior use of cement.. Charlie's solution, basically a fancy raised dry wall inner shell concept, typically has a ~30 year life before batons and plaster/insulation degrade and damp/mould penetrates, certainly should provide a better U-Rating, terminal conductivity is limited to the wooden batons and that seems to be his No1 concern. Future concern is the stone and mortar health behind the shell (degraded lime due to lack of breathability) and mould builds up on the inner wall surface. Unless you incorporate some air pocket ventilation between the gap of outer shell and inner solid wall to wick away the moisture and control/reduce mould growth, such a wall gap ventilation system would also also help preserve the wood batons extending the life of his solution, help preserve any stone & lime mortar with his walls. Technically it would be interesting to know the temp difference between that inner shell (outer surface) and the inner wall surface and also the humidity of the air gap over time to identify and help ID level of mould and moisture damage.
Thanks Charlie, as always, an open and honest debate covering pitfalls, alternative opinions, ideal solutions and then the rationale of the chosen compromise ! Some great information in this on a subject that is a minefield !
Great video Charlie. There’s an interesting EU project called Ri Build. It’s essentially research being done into the best approaches for internally insulating historical buildings. They have a calc that helps determine the recommended maximum amount of insulation for a given type as too much can introduce potential issues with timber rotting and cracks forming due to frost.
Thanks buddy - that's really interesting. I'm actually going to go with a breathable system now from SWIP. There'll be a video on this later in the year. 👊
@@CharlieDIYteHi Charlie. Any progress with SWIP and your video? How was your experience? I'm looking at their products currently but need to find a local, accredited installer first.
When I’ve insulated solid brick walls, I’ve used 50 mm celotex/kingsman straight against the wall, fit the insulation to the walls through 38mm battens, set out to suit the plasterboard, and the 12mm plasterboard to the battens. You can now run cables in the void, cut out drying holes to plasterboard, without damaging the insulation, which is all kept intact & sealed.
Love the video and detail! I am in the process of applying IWI on the front external wall of a Victorian terrace. I striped back to the brick work, some which showed clear signs of spalling; not surprising given the air gap caused by Dip and Dab gypsum plasterboarding over the original Lime plaster (creating a cavity where moisture could not escape). I have applied around 30mm of Diaphonite Thermactive, then fixed 60mm Uditherm Woodfibre board on that with insulated screw fixings and using the a wet layer of Diaphonite as lime adhesive. Not sure about the results yet but interested in next winter to perform analysis to the temperature, humidity and thermal imaging (not to mention out gas bill!). Just another thing, it was pointed out to me by a builder who works at CAT that there are common misconceptions about interstitial condensation (dew point moisture) and general moisture caused by cooking, cleaning etc. As I understand it, the latter has very little to do with mould growth within the wall structure. Interstitial condensation just requires some cavity where moisture will condense from any air which pretty much always has a certain amount of moisture in it. With that in mind, a safer approach is to simply allow the moisture to escape. Lime is also alkaline and anti microbial. If anyone is interested in Diaphonite or other insulating Lime plasters, I would recommend contacting Carrington Lime in Gloucestershire who run practical and online courses/seminars on the specific products.
Interesting video as I’m currently looking into this for my own house. I have used a product called superquilt in the past on other building projects, and it’s very effective. Not only does it provide a lay of insulation it is also a vapour barrier. You just have to make sure you tape the perimeter and overlap with silver tape. You simply batten your walls and counter batten over the top. Seems to be the best product to stop any cold bridging. I thought I’d share this with you
Thanks Craig, that's interesting. I have a wall on the south side that can't be insulated with anything too thick due to a doorway that's already tight so I'll put that into the mix 👊
VERY GOOD CHARLIE YOU IDENTIFY ISSUES & THEN RESOLVE THEM YOUR BEST BET IS YOURSELF I THINK YOU ARE A PROBLEM SOLVER, DISREGARD ALL ARMCHAIR GENERALS. REGARDS TOM😊
Hey Charlie, I haven't watched it all but there are a lot of options to insulate with lime whilst still maintaining a vapour open construction. There are cork insulated plasters which can give a good u value, also wood fibre with lime plaster would be vapour open too.
This is a far better option IMO. Insulating breathable lime render directly onto the masonry. Vapor barriers and whatnot to keep internal moisture out of the space between the plasterboard and the masonry are never going to be truly airtight and therefore moisture in the air WILL find its way behind at some point.
Great video Charlie. I'd definitely install an MVHR system if you can. I renovated a 1790 farmhouse in the French Alps, wanted to expose the stones but Mairie insisted on render so I insulated outside with Kingspan K5, (fireproof) and rendered over that, then lime plastered inside, external walls, plus lime wash paint. Dug down, underpinned and insulated the foundations, dug down rafted concrete floors on 300mm foamglas gravel then underfloor heated everything. The house is at 1100m, it's about 250m2 and costs about £1500 year to heat and DHW.. where the temp is -5 to -15 for appx 3.5 months whilst house is 22°. I'm a sparky but did the design, planning and work myself. Took a while mind you ! Love the channel....
Thanks for that mate. Wow, what a project!! Sounds similar to what I'm having to do right now with foundations missing on a corner of the kitchen. I've decided to go with breathable insulation inside now, given the exterior render isn't breathable. Also lowering the outside ground which will help damp issues on the walls.
@@CharlieDIYte sounds good, lower the ground and try and incorporate as much land drainage as possible. I like those humidity monitors your have, An MVHR will give you a finely controllable tool to manage humidity and hopefully stop any potential condensation before it starts.
@@CharlieDIYte Hi Charlie. I have the exact same problem as you, tyrolene render on the outside, solid walls. What types on breathable materials did you insulate with? In what order and method did you install them? Thanks
I have implemented external insulation along with mechanical ventilation with heat recovery (MVHR) in my home. While it may not strictly adhere to vacuum requirements for MVHR, this combination has proven highly effective. The system functions like a charm, preventing condensation within the house and maintaining significantly lower humidity levels. This integration has successfully created a more comfortable indoor environment, showcasing the practical benefits of combining insulation and mechanical ventilation for improved humidity control.
Hello, what is MVHR brand you got installed? cost of installation? Does it work in conjunction with air source heat pump and under floor heating? thanks for the enlightenment.
I would have dabbed 50mm PIR to the walls and foil taped the joints, then mechanically fix the boards to the wall with plastic 10mm board fixers. That way you’ll get the walls nice and straight. Next, I’d have fixed the plasterboard to the surface of the PIR with expanding foam adhesive. Soudal do a great glue and very easy to use. I never buy insulated plasterboard as it’s twice the price. Battening a wall creates a cold bridge.
In our solid walled home I sealed round the edges of whole sheets of foil backed PIR (celotex etc) with silicone and put that directly onto the plastered wall. Then fix 50x25 tile battens over this to mechanically fix the boards to the wall foil tape the joints then fix the plasterboard to the battens. Gives a nice 25mm warm void behind the plasterboard for the sockets etc with no interruption to the vapour barrier. The whole wall is completely covered with insulation no battens in the way. Also no chance of the battens rotting as all on the warm side of the insulation. Would say the walls are almost air tight in theory.
@@asilver2889 more of a belt and braces thing to help with airtightness between the board and the wall. The boards are squashed so tightly to the wall by the mechanically fixed battens I very much doubt any moisture that might find it’s way past a failed bit of silicone in 20 odd years will cause much of a problem.
When doing my bedroom i battened the walls and as the walls were so uneven i used plastic shims to bring them off the wall then used a closed cell expanding foam sprayed behind the battens to stop them flexing, reduce sound and act as the damp proof membrane. I trimmed back any spill out the side of the battens with an old saw then filled between with mineral wool insulation. Then went over all this with my vapour barrier and plasterboard.
That's an absolutely top job. Great work. Yes I've considered rock wool. It means having to install an additional vapour barrier as you say but it's not totally off the table right now. 👊
Excellent Information Charlie, It’s a cost that you have to be prepared to lose some floor space to gain comfort as well as peace that your property is not rotting away behind the seems. I’ve no problem with loosing some floor space to do this but like everything else in life,,,,, Quality comes at a cost. Thank you so much for sharing, it a great reference video that I’m going to share with a lot of folks. 👍
Does the foil go to the outside or inside with gyproc , if inside wouldn't that cause damp on the outside to seep through the gyproc ? , I have lathing plaster and would like to strip plaster out and replace with foil backed gyproc on to battens with foil to face outside in kitchen with foil insulating sheets on to the gyproc then kitchen cupboards on to that , without the moisture issue it would be easy lol
I've just insulated a north-facing kitchen wall using 4mm cork roll, bonded, full contact, with tile cement (diluted 1+5/PVA+tile cement), to the existing plaster/wall. (The wall is a cavity wall). Hopefully this will mean there's no void to collect moisture. The result so far is signicantly reduced condensation, with a marked increase in temperature of the room. The cork was treated both sides with a diluted PVA 'wash' prior to application, to help with cement bonding. Is working for me!
Well thought out. Besides basic logic and research specific materials a great plan. Allow me to share a moisture battle of my own. (not applicable for a problem like yours) As you know I own a lot of garages and one of them had a half brick wall and with heavy rainfall for a long time at a time moisture came through the wall. What I did was, I gave the outside a special invisible impregnated coating, throwing water at it will make it drop on the ground or stick at the wall as drops. Inside I used two component basement coating, once mixed you need to apply it within 40 minutes and it looked like there was a plastic on the wall. Since it still was a cold wall I made a wooden framework and in between I glued polystyrene foam boards against the wall, a tiny thinner than the wooden framework so there is some air between the polystyrene and the wooden panels. Made two holes in the wall, front and back of the garage, with air vents, problem solved. That two component basement coating is so good, it really seals off any moisture coming through the wall. There is no heating in the garage so this was the best solution and no mould. Success with the walls, keep us informed !
Not sure if you have it in UK but in NZ theres this product called Crystal, its a non decorative coating you paint/roll/spray onto concrete. The crytals in it actively seek out moisture in the concrete and it becomes a complete waterproof sealer. Typically used in existing subfloor basement concrete walls.
Thanks, that's really interesting. If nothing else could be really useful for the bricks below the dpc. A quick Google suggests we don't have it here though ..
@@CharlieDIYte bit lazy of me its called Crystal Proof. I believe theres many brands that make a similar thing but here its made by Cemix which is probably an Australian company. I believe most local concrete workers probably know the equivalent in UK?
We have something similar in Romania, but we call it glass water. You apply with a brush and roller and make the wall 100% waterproof and block water infiltration from outside to inside
I don't know if I was overkill or not, but I built a stud wall 50mm from a granite wall with 100mm deep timber. I then put Kingspan pir 100mm with gapo tape. Where the sockets are I put two noggins directly above and below the box, and a bit of ply out the back and expanding foam to fill. Then I put a green vapour barrier up, and plaster board ontop, and got a plasterer in. I then used a vinyl mat paint as I hope it will block vapour also, but for me the 50mm out the back provides a ton of ventilation from the attic. Let me know if anyone can see anything wrong with the setup as I have all the other bedrooms to do this summer!
Great video Charlie. I've just done similar but pretty much made all the mistake that can be made. Dot and dab'd PIR board to solid stone walls then thought about fitting pattresses afterwards. Lessons learnt and this is the first room so won't be making those mistakes again.
Philip I was the same with the K118 upstairs. Keep an eye on my channel was I'm attending a 2.30 hr training course today with one of the leading breathable insulation providers. I'm be doing an update video on it soon 🔜 👊
That was an interesting video. Only thing i would add to that spec' is a sheet of 11mm OSB behind the plaster board. Not that it will have any meaningful affect on either vapour or heat control, but it makes fixing things (shelves for example) easier. Nothing worse than trying to fix a 500mm wide wall cupboard that isn't widen enough to span between the studs or is wanted in a position that won't coordinate with the studs. Apart from that, i am with your design rationale all the way!
If you get any kind of penetrating damp from the outside you can still get mould issues, I worked for a guy who wanted his whole house done with insulated plasterboard dabbed onto the walls it was in an area with a natural spring and sometimes a high water level so I advised him against it but he insisted the walls were dry so I did what he asked only to find that he got mould spores behind the plasterboards. What people and companies forget is you only need a small bit of mould that will spread and spread even with intermittent damp.
Yes I'll definitely get rid of the mould Fred. I'll probably spray it with a bleach solution or something like Zinsser Mould Remover, assuming I don't hack off the render entirely.
I'm of the opinion that voids will always have some amount of air 'leakage' into them no matter how much foil tape and we'll made the walls are. And then you've got damp air trapped in a void with a cold wall for the moisture to condense on and with very little way for it to evaporate (after all, you've just spent lots of time foil taping it etc to try keep it out in the first place). Which is gonna lead to mold growth on the wall. It's a similar debate that the Diy campervan community has, spray foam vs wool, with a void between the insulation and the vans body skin to let it breath? Or let the insulation touch it and risk having it rust. I honestly can't think of a good solution and I've been thinking about this for 2 years now. Good luck I look forward to am update
The difference between a camper van and a solid wall though is when moisture condenses on a solid wall it will be wicked out towards the outside of the house where it will evaporate, that’s how old houses were designed to work, assisted by well breathing lime mortars. Until someone cement renders the wall, restricting the escape route for the moisture.
I live in a 200+ year old stone wall property was completely gutted and renovated in the late 60s. The walls were covered in some sort of bitumen, then a stud wall that doesn't touch the stone was put up, and covered with 3cm thick foil backed plasterboard. I was able to learn all this using an inspection camera when fitting shelves. It seems to work fairly well, although the walls are about 50-60cm thick from outside to inside.
Thanks Andrew. I'm still researching this insulation issue as I find it fascinating just how complicated it is/ difficult it is to get right. I feel I slightly skirted over the breathable options so I'll try and do another video with my findings.
Hi Charlie, you say using lime plaster wouldn't be warm, however I see other breathable materials on the market like Diathonite Thermactive, which is lime based plaster but has a thermal conductivity of 0.037 W/mK, which although performs only half-decent when compared to something like Kingspan option, but it wouldn't require the void, meaning actually you could add a thicker layer, which then starts matching the Kingspan! On top of that I see that other options like Wood Fibre or simple sheep wool also have thermal conductivity of ~0.038 W/mK, which likely would make this a simpler project and cheaper. I haven't calculated the difference in cost, but I dare to say it would make it a lot less complex and potentially less risky? What is you opinion on this?
@@montvydasklumbys7584 Now try to heat up it after insulted from inside. As soon as heating is off it cools instantly down. Air alone doesn't hold much heat.
Solid strategy. Only think I might consider is if you’re looking to put cabinets on the wall I would think about using double thick plasterboard and substituting the inner layer with ply behind wall cabinets for strength.
Thanks. Yes I'm thinking of doing this. I'm also just researching all options including breathable to make sure I'm not missing a trick. Will do a video update at some point.
What's important to me from this video is you have taken the time to really think about the insulation - which I find hard to do with work consuming my life. Thank you for the research
You are correct in the middle... you should use a breathable insulation like wood fibre a carrier board and then lime render.... it doesnt have to be cold and only use lime render. You shouldnt use a vapour barrier on a solid wall because you will have the exact same issue you are trying to fix.
Really interesting series Charlie. We live in a Grade II listed building, so although I agree with your arguments for going with internal insulation, it isn’t unfortunately an option for us as we’d never get listed buildings approval for the works (and would end up with an unsaleable property if we went ahead without approval). Over the years, gypsum plaster has been used to reskim some walls and damp/mould is a constant issue in these areas (presumably because it’s less permeable than lime plaster). Even with a decent central heating system, log burner and moisture control, getting RH to under 60% is almost impossible. Upshot is that we will be moving and wouldn’t buy a listed building again, sadly there are just too many restrictions which prevent them being suitable for modern living 😢
Thanks Darren. It's sad isn't it how the restrictions on heritage stock make it so difficult to live in. I'm actually researching breathable insulation right now so keep an eye out for the next video. May not go down the PIR route. 😉
Yeah it's criminal that so many listed buildings will eventually be destroyed by the very people supposed to be protecting them, because of imposing some crazy rules. The sad truth, is that it would be wise to stay clear of these buildings.
Aren't you going to get cold-bridging across the timber? That's why you'll see recommendations to use insulated plasterboard as a layer over the top of the battens, as well as insulation between the battens.
I just came to the comments to point this out, cold bridging through the timbers. You could end up with shadowing on the walls. Also, the 1x1 timbers could be omitted if you ensure the PIR between battens is fitted flush with the front face of the battens. I retrofitted IWI to our solid wall house using a similar technique but created a 30mm ventilated cavity behind the battens, essentially built stud walls internally in front of the brick walls. The house is very comfortable and retains heat well.
Id gyp-line the walls with rubber gromits to reduce cold bridging. Use 75mm insulation on to the gyp-line , tape the insulation amd then board over ot. This ensures that there is an air gap for the brick to breath, but would do what you want
From what I've understood, the best option is to go for least breathable to most breathable (inside to outside), if space allows (which is the main problem in the UK and why we love PIR). So that would typically be a layer of PIR just under the plasterboard which also acts as the VCL if done right. Beyond that, lots of breathable stuff like rockwool. This assures that any moisture that does pass through (which there will always be, screw penetrations, gaps in tape, etc. always assume there are gaps unless airtightness tested) has a sufficient 'gradient' to evaporate and not condense by immediately hitting a brick wall of impermeable material. I also noticed that in your bedrooms you did a 25mm layer then a 50mm layer over the top. Apparently this is non-advised due to the gradient stuff I mentioned before. You typically want the thinnest layer at the top, and the thickest layers where it is colder, this helps avoid any interstitial condensation. Last thing I'd say is those metal bracket things you mentioned for the socket boxes? They're duff, IMO. All they do is create nice little bumps on your flat plasterboard when it goes over the metal hooks. Stick to 4x1s for secure anchoring of backboxes.
I battoned and insulated the entirety of a derelict cottage that we bought a year ago. It's very warm now and we're very happy with it. We went with 80mm xtratherm and used 4x2 for the batons. There was a few mm gap behind the insulation then as well so we didn't bother putting more batons on top because we were tight for room space. Very happy with how it turned out.
I also bought the Gapotape but found it a bit of a nuisance so ended up not using it mostly and just made a jig to cut them all the correct size to fit tight in the batons. Foamed in any gaps with Hermatic expanding foam
This is such a good video! The approach makes complete sense however I wondered if sealing the wall could trap rising damp? Or is rising damp not an issue at this property? I'm not trying to be clever here, I just have a similar challenge ahead and am formulating the plan!
I insulated my garage walls ( 4 inch brick wall ) to turn it into a habitable room I could use , this is the order how I insulated it 1) 25mm pir tight to the wall and foil tape joints 2) 4x2 timber stud wall with 70mm pir in between to allow a gap for wiring to sockets etc 3) vapour barrier stapled to studs 4) 25mm pir over stud wall and tape joints 5) 12.5 mm plaster board The first 25mm layer of pir was to stop any thermal bridging. I had to put a warm flat roof on the garage so that meant there was no air flow to the brick work unless I put an air brick in top and bottom of the brick wall but that meant I would lose more floor space in the garage, so I put liquid dpm on the walls to stop any moisture coming through the brick from the outside. I also applied liquid dpm on the garage floor and dpm plastic membrane on the garage floor and lapped it up the wall by 500mm . Any comments would be welcome if you think I am going to get problems by doing it this way
Looks like you have sealed both sides of the inside and the wall. If you have single skin brickwork then you can get some wicking in of moisture from the outside and that would stop it but the issue you have is your are effectively trapping the moisture inside. It depends on how much moisture you have in the room and how much ventilation you have. If you had a bathroom/kitchen etc in there then you’ll need some form of extraction and a way to bring in less humid air. It’s done now so I wouldn’t worry about it. Just buy a humidity meter and keep an eye on the levels and if they get excessive then consider a de humidifier or another solution.
How much better insulation do you get from a PIR with a lambda value of 0.0022 compared to the standard 0.0037 ? In my country outer walls are getting up 700mm thick on new houses because we need more and more insulation to live up the minimum requirements. I wish there were somewhere you could compare how much more insulation it would take to get the same U value
@@otofoto Correct and that is the problem in my view. The house becomes very expensive and not much space inside compared to outside. That is why insulation like PIR is potentially interesting. If it is possible to get the house approved for thinner walls then it becomes a better option
@@jwester7009 Better look at silica gel insulation. It is inorganic and non-toxic. Unfortunately none of insulation for older buildings is economically viable. It never pays off and after 10years there are new codes and again need to change everything. None of such investments are paid off, pointless.
From Roger Barnes youtube video, "Escape to a French Fishing Port". Roger is an architect and working on an old stone house. To add insulation, he is adding 3cm of clay and hemp to the interior stone walls (sprayed on) and then covering with a lime plaster. You can check out his video, he explains it all (with diagrams) much better than i could.
I've been working on insulated my parents 200 yr old house, which has sold walls (only the ground level) with internal insulating like render. Called like green ultra. Only did this on the external walls. 20 yrs ago builder just dabbed plasterboard all damped over time. Now been removed. Can feel the difference think I got about 50mm of insulation in some areas as walls are not that straight. Bowing in areas trying to get it flat. Can feel the difference. Wouldn't mind getting a thermal camera to see the temp diff between the ground and top floor as top floor is still solid walls. With some plasterboard on some of the rooms.
Thanks for sharing - does look good where you're wanting to stick to lime render. How have you found building it up to 50mm as it looks like 30mm is the recommended max? 👊
@@CharlieDIYte The wall was pissed as a fart and bulging in places. The areas below the window for example the applied layed of insulation is about 25 to 30mm The recommended application is between 10mm to 30mm per coat, cured for a period of time, keyed at some point. After some time has passed another layer may be applied to build up the thickness. Which in my case was about 50mm. Would deff not apply anymore than a inch at a time as it may fall off... Taken a few weeks to get it to where it needed to be and it's almost completely flat now. 3 coats and some areas and 4 in others as i say parts of the wall bow and bulge. It was very easy to mix and apply. Its nothing ive ever used before. Its ever so light yet sticky. Think of it like bonding but its 10% of the weight, wonderful stuff if you want the building to breath. At the moment a small radiator is in that room to help get some warm in that room. The room is maybe 5metres by 4.5 metres with really high ceilings. It now doesn't feel as cold as it was before the insulation. The rad is only a tiny thing single panel single convector. 500mm x 500mm. Deff would recommend this stuff if 1 wants to let the building breath. It's letting the damp get out that has been covered by plasterboard for 25 yrs. 1 wall when I took off the plasterboard was damp to touch. Can see it physically wet. Just soaked my hand. Behind that plasterboard was some sort of square corrugated tar cardboard that I've not seen before. It is still drying out after a yr. Damp patches are appearing. But at least its not going to be moldy.
Internal wall insulation in cold climates (eg UK) is a bad idea full stop. Your building will rot. I know - I've done lots of it. Will only use external insulation in future. It only works if: 1) You fully seal the inside with a perfect vapour barrier, which is almost impossible in an old building. What do you do about joist ends? And in the space between floors? 2) You have a breathable cavity between your insulation and the original wall. With holes drilled to the outside. 3) You strictly control the humidity inside the house by installing a whole house MVHR system. 4) You make sure you don't insulate too well! There needs to be some heat lost through the external walls to drive the moisture out. If you do all this it will work and be fine. But it's rare to find tradesmen who will tape every single pinhole, unfortunately over time MVHR systems won't be maintained, roofs will leak into your cavities, and because you've insulated and sealed on the inside, you WON'T BE ABLE TO SEE THE LEAK until it's rotted your whole wall.
As you will will know Charlie internal insulation on a old wall is a risky business and there is no 100% solution to it I feel in my experience counter battern it so that there is an airflow across the wall but you will have to vent it possibly from the outside somehow also use stainless steel screws in wall when battening
And I'm sure you already checked afew different areas on different walls to make sure the bricks weren't used as a fire stop at doors or any openings or not even fire stops just to hold the small dukes we called them ,bits of wood built in to wall centre to fix door frames Though as I say you I'm sure have thought of anything I could 👍
Have you ever heard of Gypliner ? Or its generic equivalent. It's been around for at least 30 years. Granted I just flicked through your video but I'm puzzled by your fascination with timber in these circumstances. If you are attaching timbers to such a wall what is your method of keeping the wall plum and straight in a time/motion efficient manner ?
Second this. Gypliner type system or a gypliner independent wall lining system would be a much more modern solution. Negates any issues with cold and damp bridging and not much difference in cost compared to timber battens. No shrinkage either so might negate need for the Gappo tape. Could consider installing weep vents in the cavity void for airflow.
Hi . I dont see any update to this video in relation to the method you decided to use to insulate the walls, or have you a link to the update if it exists? thanks
Thank you for this content and being so encouraging to have ongoing communication. I'm hoping to add some insulation to my internal walls but am wary of moisture problems. It's incredible how little good information there is out there when it's really such an important topic, especially given the cost of heating a home currently!
Another approach would be to use moisture conducting insulation. Any condensation that happens inside the walls would than wick to the inside and dry off. One would use stuff like cellulose or woodwool as insulation and woodpanels or clay-bricks as inner wall. Since i've heard of this concept I've come to the conclusion that breathable wall materials actually mean moisture wicking materials (it makes no sense being able to breathe throu clay or lime)
Indeed, I've been looking at wood wool insulation like Lime Green Warmshell, a system from Steico and most recently UdiTHERM NF. These allow vapour to move through, and help to contribute to the thermal mass of the room. Admittedly one does need to use vapour-permeable materials all the way through.
Yes Sascha, the term breathable really means 'vapour open' so that moisture vapour, but not air, can make its way through. It should still be airtight, confusingly. Many conflate 'breathability' with ventilation. I was baffled until I did the training and research.
I insulated two flats i own as they had had a few mold problems. and i stuck a heat exchanging ventilation system in. One flat was fine but the bloody tenants in the other climbed up into the roof space and disconnected the power to their system as they thought it cost too much to run then a year later they complained about mold returning. what i found ironic was they had put a tumble dryer in the bedroom where it had become moldy as they didnt like going outside in the cold to hang up their washing. As you say if you keep an eye on the humidity and open windows or use ventilation you can stop it happening but a lot of the time its down to the people in the house trying to seal themselves in that creates problems.
I have solid brick wall with no insulation. I used battens and superquilt insulation. After battens again then plaster board this gives you a service void for electrics and plumbing. Also the foil insulation has built in vapour barrier. I have completed this in three rooms so far and a noticeable difference. Uses approximately 70mm thickness
Charlie, so the process of insulating walls internally seems a lot more complicated than I had anticipated. I have a tiny box room in the corner of the house so it is cold, but I don't want to lose the depth against the walls that you are doing. I don't even really want to lose say 1 inch of insulation + 1/2 inch of plasterboard. So, I am wondering if you have ever heard of any kind of insulation boards that do not have plasterboard over the top and that I could paint over, or even cover with something thinner to give a reasonably smooth surface - something like a reinforced wallpaper. It would be great if the insulation board were impervious to moisture in order to provide a vapour barrier. Maybe they make something like this for use behind tiles in a bathroom. I don't know. Anyway, what I am asking is whether you know of a method of insulating walls that will be as thin as possible, given that I don't really care about a perfect plasterboard finish.
You could check out products like 'Qboard' - which is typically used in bathrooms and can be tiled directly on top of. They offer several thicknesses (4mm - 5cm or so), are fully waterproof and provide some level of insulation (apparently). I'm not sure you could wallpaper them directly, but I suppose you could plaster then paint / wallpaper. Will it stop the wall you stick it to from building up moisture? I have no idea at all! Good luck ;)
Thanks for sharing your process, love your videos. Your focus seems to be on moisture from inside condensing in the cavity. Is there any concern of water from outside coming through? Other than protecting the battens with vertical dpc strips is there nothing else to do there, e.g. no tanking needed? Another thing I worry about are air gaps: I guess air gaps increase insulation effectiveness. But wherever air can flow, moist air can flow, so why not fill air gaps with foam? Just one missed spot tape would let air in no? If the dew point is in the middle of impenetrable foam wouldn't that be better?
As far as I can tell vapour doesn't just spontaneously condense in the middle of materials, even if this is where the dew point occurs, it has to condense on the coldest surface of that layer. I think Charlie is using an air gap at the back just encase there is any moisture issues with the solid walls then another on the PB side as a service void so he can have ridiculously deep back boxes.
Suppose all well and good if you have the available space to shrink the room by net 120mm per external wall after hacking off the old lime plaster (in my case). My kitchen is 2200mm wide so just not a realistic solution. Chucking up external insulation over period features on a victorian property....the net zero lot can chuff off!
Hi Charlie. Interesting content, as always! You forgot the include a link to the thermal imaging camera - I'd be interested in getting one, if you could share the details of it. Cheers!
Not wanting to sound too unorthodox, one could simply not attach electrical conduits to the brickwork. Pull up sockets in the kitchen worktop instead and electrical trunking in the floor beneath kitchen cabinetry? Just a thought.
@CharlieDIYte fair enough. When you mentioned the back boxes interrupting vapour control layer etc it just reminded me of a project I did 10 years back in Muswell Hill. Getting perimeter insulation in between slab and wall is probably the most important aspect of these domestic projects. Making sure the slab doesn't act as a cold bridge etc. Humble Architect in Salisbury. Cheers
Taking of condensation, I've got an issue with our cellar. The water vapour is very high this year and the cellar is particularly damp ...we can't keep the relative humidity down at all.
I insulated the exterior with EPS then silicone rendered, couldn’t do internally as would have lost so much room (1740 cottage), moved windows forward, extended barge boards but luckily soffits were big enough, have to say works wonders….
@@CharlieDIYte I built an extension so was part of the planning, but, if the building was already rendered ( like mine was) and your replacing like for like then no I wouldn’t have needed to. Keep up the good work 👍
From a thermal performance pov you should not leave voids in your structure. I know this goes agains common practice in the UK and it's a more expensive option but walls need to be void free in order to minimise the chance of mould, cold bridging etc. I am not at all suggesting that you stick the rigid insulation to the brick wall. That is wrong and against manufacturer recommendations and will result in issues. You should however fill the void with some form of wool insulation. I have a personal preference but they will all work so maybe go for an economical option. If you are looking for other improvement of the design, maybe also use steel framing rather than timber. It's a bit harder to start and you will need to get a few more tools but the channel allows for insulation to be tucked in and the thermal bridging happens across the thickness of the steel profile which is substantially smaller area than the timber that you use. Also, once you get going, it's faster to build than timber framing. This likely goes without saying, but make sure that the outside of your solid walls is in a good state. If you have exposed bricks treat those with water repellent (many to choose from). If you have render, you need to ensure there are no cracks as those are ingress points. Lastly, I your slab was poured with insulated perimeter, I think you may be over engineering this whole thing. It's for you to judge but there is a point at which thermal improvements become exponentially more complicated and costly. I get that this is also content generation for your cash cow but ... edit: I can't believe I forgot this but I used intelligent membranes for a similar project with great success. And yes you can dot and dab over it and you will not get mould (remember to use a primer on top of purple and under the adhesive)
Is there an breathable membrane on the external surface of wall which could be a form of render to prevent potential issues concerning interstitial and surface condensation
Yes there are breathable EWI systems. However you always need a good ventilation strategy when insulating externally but it's a far superior solution. Here's my update vid ruclips.net/video/Ou1CjwflZtM/видео.htmlsi=0Bx9zSMGiKkAi_Vu 👍
Fantastic video. I'm just wondering if it's worth all the effort, e.g. keeping the insulation boards off the wall underneath using the 1x1's, I know you want to have some aeration to combat any condensation, but any moisture in behind should be dealt with my the lime mortar they've used? What about drilling out some holes at a downward angle every metre so as to allow air into the space? The initial mould you saw might've been due to the paint finish and lack of vapur barrier, end of?
One external wall in my bedroom is only single skin. Its around 200 years old and is a vertical continuation of the "shared" wall of the terrace. The neighbouring house existed first but is only single story, it seems my house was then built some 50 years later and they put in a single skin wall against the neighbour's existing wall and then built it up to two stories. It takes a fair bit of driving rain and is quite exposed making the room very cold. I'm thinking to go the insulated lime plaster route
Have a look at this if you're going down the lime render route. Haven't used it myself but it was recommended by another viewer. www.lime-green.co.uk/products/lime-render/ultra_render
@@CharlieDIYte u put the vapour barrier staple to stud work thrn plasterboard and make air vents in wall so air can circulate which is what i have done and i habe a 100mm gap between wall and stud
Hi Charliediy, really appreciate your video very well done. I see the batons represent a significant cold bridge. Did you consider foam glue ? I used foam glue which unlike dot and dab and batons is foam insulation so no bridge and it worked. Still need vapour barrier but again foam glue on phenolic. My new project we are using breathable Lyme plaster x 3 layers plus final coat of aerogel plaster which for 10mm has same u value as 75mm of PUR board. Phil
i don't get it. the consensus is tat the most appropriate material is lime plaster right? your only issue seems to be, how to get enough energy to heat the rooms? surely its far cheaper to keep your gas boiler and just install solar with additional heat pump. that will easily be enough to toast any roo and the only additional cost is the solar and heat pump . the solar will run the heat pump so no additional energy costs
Great video Charlie, I have a similar job and this mentioned all of the same concerns that I’ve been wondering about myself (non-continuous vapour barriers, cutting holes out for sockets plumbing etc). I’d be interested in hearing how your installation went and how it’s holding up? Did you use any form of DPM behind the 4x2s or was it not necessary?
I hadn't got to that point yet but yes I should consider this, albeit with the vapour barrier and the socket boxes allowing moisture through anyway it's probably less important. For £3 a sheet extra it's probably worth it though.
Hi Charlie …. I don’t know if you thought about this … but what about a liquid dpm the stuff I use is like a black tar when it drys it’s like a black sheet .. then I just apply normal plaster board…. Does the treat for damp
Hi Charlie i have been looking for this advice everywhere thankyou! I am doing similar but my walls have rising damp (solid walls) looks like it has been plastered not lime so hopefully once removed it will subside. im considering using dry rods as a chemical dpc before using said method you are doing any advice would be great?
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I am currently renovating my new first home and I need to do this to my entire house (external solid walls) Just wondering, did you need to get Building regulations approval to do this ? I'm a little confused where I stand with this. I have to do attic, walls and insulate under the raised floor.
I wonder if you have secured/ painted external walls. To be honest, I wouldn't go for that internal installation. Better would be external for longer run.
I built a two storey extension as a granny annex in 2003 using 40mm laminate plasterboard dob and dabbed onto 9" solid block work. I recently put new doors and windows in and uncovered a lot of the original wall surface. Not a hint of mould or condensation. External walls are rendered pebbledash. I am now doing the same to the main house external walls as i replace the old leaded light windows. If you try and consider all the issues you come to the conclusion its not worth it bearing in mind the cost and no one can get give a definite way to do it. however I need to be warmer as i get older in the winter. This time I am using adhesive foam which almost removes any gap behind the insulation as it needs perfect contact (keep pressure applied for half-hour plus across the whole board with temporary wood support and of course mechanical fixings). We do intend to open windows as much as possible to reduce humidity issues. in 10 years time I'll let you know if it worked!
Amazing to find a builder who actually does understand and considers how to refurb properly and follows or improves on building regs. If only every builder did this.
Thanks 👊
Not a builder. A you tuber that takes every thing he reads as gospel.
Eager to see how you achieve this.
I am going through a renovation myself and we have decided against internal wall insulation due to several factors. and will therefore try to attempt external insulation in the future.
I spent ages reading about how to insulate, and even airtightness, and too many approaches out there to say the least. It was too confusing and tradespeople did not help.
Interesting video Charlie.
Not to be only pointing out issues but I see two potential problems with this arrangement.
Firstly there are many unventilated cavity spaces right where the dewpoint position is (internal face of the brickwork wall), surely that is perfect conditions for mould.
Secondly, with the batten fixed directly to the brickwall they will act as cold bridges, a studded frame build independently say 20mm off the brickwork would have avoid the cold bridge, or even a "warm" batten with 25mm insulation fixed behind the batten.
Regardless an interesting subject where it is near impossible to satisfy all requiments!
Ideally, that void should be vented in someway to outside air
Weep vents maybe
@@alanpowell24 So when it's -5 outside you've got air of that temp circulating inside of your house walls. This is not a good idea.
@@lksf9820 The mould won't grow at -5, effective... :)
Positive ventilation unit pushing air into the cavity space if its a continuous maze gap with trickle vent exits? would that cause any issues with the inner shell?
Great video Charlie, I've been getting involved in external and some internal insulation, I have solid walls and have researched this complicated subject, I have used alutrix vapour barrier and a combination of foam fixing and insulated plasterboard. you can end up chasing cold bridges until the cows come home . Somewhere the vapour barrier has to be breached. As you rightly say, ventilation is essential as moisture will build up eventually. Interestingly I ripped down 4mm conti board pinned to batten on my dining room walls and found the external walls bone dry. Unluckily my lead roof laid 20 years ago on a warm roof where no barrier was installed erupted and dissolved to white dust. You live and learn.
I will be doing this very shortly in my two front rooms. I have decided use PIR straight onto the brick wall, batten a frame in front of it and screw battens to ceiling and floor joists. This way there is no compromise in the insulation. Socks can go in the void behind the stud wall.
There are a number of internal wall insulation options that are breathable which is the best option as you get you u-value. These include but not limited to wood fiber insulation and lime render with cork or pumus stone in it put on at about 50m thick. (A friend did the latter on his listed cottage and it's amazingly warm)
What about air tightness / air changes per hour?
@@inh415 breathability and air-tightness are two different things.
Materials like wood fibre can help to prevent moisture buildup in walls by absorbing any condensation at the cold surface (assuming good contact with a breathable adhesive like a lime mix). The moisture can then be wicked back through the insulation, and when the internal humidity drops breath out into the room again.
Air tightness on the other hand prevents penetration of air from outside. Wood fibre insulation, whilst not completely air tight, does obstruct airflow, and you can get vapour-open air-tight materials, both as membranes and as paint-on treatments. And intelligent valour membranes can be used to prevent/reduce vapour penetration into the wall from the room, whilst still allowing vapour to breath out into the room (usually at a certain relative humidity and temperature range).
@@DevAnubis Yep, i'm looking at this option as well, wood fibre boards from STEICO. It fits in with the "design philosphy" (if you can call it that) of an old solid brick walled house. Back in the day they didnt have the means to stop moisture at any point (sandstone block foundation) and just let it come and go. And they ran direct wood-fired stoves which kill moisture so fast you wish you had more lol. Covering up these walls from any side with anything that stops water is asking for trouble. The wood fibre board solution sounds almost too good to be true as the installation looks fairly simple and doesnt require several layers of whatnot.
Woodfibre insulation fully bonded to the wall with lime plaster over or Diathonite insulated plaster would have been the best option. Standard best practice is to not leave a cavity next to the wall as you will get mould growth just like you did before. It is almost impossible to prevent air ingress into that cavity. You also need to remember to insulate between the joists in the inter floor void next to the wall having parge coated first around the joists to prevent air ingress.
Thanks Alex, appreciate you sharing that. 👊
Hmm, yet perhaps to reduce service penetrations you could perform your insulation then have a horizontally battened service cavity with airtightness layer behind traditional plasterboard. This means religiously taping that barrier behind each socket box and penetration before mounting the plasterboard.
Better still simply tape the airtight barrier to the Lime insulation, then attach the electrics taking care to seal around the screws. The same dedication would have to be taken for the screws mounting the plasterboard battens. Then attach the boards..
Good stuff. Having looked into internal insulation it's clear that it's a murky area with unclear best practices. Props for trying to tackle the issue and bring clarity on different options
Agreed - I've been upgrading my home, which has a cavity wall that the previous owners insulated at some point. Trying to get any consistent information on how to boost the insulation is nigh impossible. I went with a dot-dab insulation approach like I saw on this channel before and it has been extremely effective for me in one room, now considering whether to do likewise in other rooms, it looks like there might be ways to up the game.
@Alex Barlow dot and dab is fine for most walls as long as there is no shelving or units built there like a kitchen etc.
It becomes a pain in the backside though if you decide to start putting up shelves or units after. If its like 50mm insulation or higher.
We went with battoning the walls like Charlie here and used two 2x2 stacked on top of each other which allowed us to fit 80mm insulation in between it with a few mm gap for air. We're very happy with it and it's very warm now, even during the last winter. But we also upgraded all the windows to triple glazed from Poland as well.
Definitely recommend but either way, insulating is such a great investment.
We insulated the whole lot for about £6000 and got the windows for £3500. All the work done ourselves.
What brand are the windows?@@fgcvhhbvjhbj
I would use Steico's system of applying wood fiber board to a masonry surface and then finish with either a vapor permeable wallboard or a lime plaster which is also vapor permeable. I would then finish with a vapor permeable paint. You are relying on a cold air cavity to control moisture which will over time probably fail. You are also not allowing the walls to dry out causing them to deteriorate over time. The walls were made to breathe, you have to let them.
Charlie says its a '2 brick course with no cavity' - we dont know if its a lime mortar pointing(but he seems to allude to that with the proposed lime insulation solution eval). If he currently has a "mix and match" lime and cement mortar pointing(which is typically of older houses with a mix of more recent renovations). IMO Even with a lime internal plaster composite integrated insulation layer(no gap) it may not resolve the damp penetration patches and cold spots due to any prior use of cement..
Charlie's solution, basically a fancy raised dry wall inner shell concept, typically has a ~30 year life before batons and plaster/insulation degrade and damp/mould penetrates, certainly should provide a better U-Rating, terminal conductivity is limited to the wooden batons and that seems to be his No1 concern.
Future concern is the stone and mortar health behind the shell (degraded lime due to lack of breathability) and mould builds up on the inner wall surface. Unless you incorporate some air pocket ventilation between the gap of outer shell and inner solid wall to wick away the moisture and control/reduce mould growth, such a wall gap ventilation system would also also help preserve the wood batons extending the life of his solution, help preserve any stone & lime mortar with his walls.
Technically it would be interesting to know the temp difference between that inner shell (outer surface) and the inner wall surface and also the humidity of the air gap over time to identify and help ID level of mould and moisture damage.
Thanks Charlie, as always, an open and honest debate covering pitfalls, alternative opinions, ideal solutions and then the rationale of the chosen compromise ! Some great information in this on a subject that is a minefield !
Thanks Andy. You're right it is a minefield 👊
Great video Charlie. There’s an interesting EU project called Ri Build. It’s essentially research being done into the best approaches for internally insulating historical buildings. They have a calc that helps determine the recommended maximum amount of insulation for a given type as too much can introduce potential issues with timber rotting and cracks forming due to frost.
Thanks buddy - that's really interesting. I'm actually going to go with a breathable system now from SWIP. There'll be a video on this later in the year. 👊
@@CharlieDIYteHi Charlie. Any progress with SWIP and your video? How was your experience? I'm looking at their products currently but need to find a local, accredited installer first.
When I’ve insulated solid brick walls, I’ve used 50 mm celotex/kingsman straight against the wall, fit the insulation to the walls through 38mm battens, set out to suit the plasterboard, and the 12mm plasterboard to the battens. You can now run cables in the void, cut out drying holes to plasterboard, without damaging the insulation, which is all kept intact & sealed.
Love the video and detail! I am in the process of applying IWI on the front external wall of a Victorian terrace. I striped back to the brick work, some which showed clear signs of spalling; not surprising given the air gap caused by Dip and Dab gypsum plasterboarding over the original Lime plaster (creating a cavity where moisture could not escape). I have applied around 30mm of Diaphonite Thermactive, then fixed 60mm Uditherm Woodfibre board on that with insulated screw fixings and using the a wet layer of Diaphonite as lime adhesive. Not sure about the results yet but interested in next winter to perform analysis to the temperature, humidity and thermal imaging (not to mention out gas bill!). Just another thing, it was pointed out to me by a builder who works at CAT that there are common misconceptions about interstitial condensation (dew point moisture) and general moisture caused by cooking, cleaning etc. As I understand it, the latter has very little to do with mould growth within the wall structure. Interstitial condensation just requires some cavity where moisture will condense from any air which pretty much always has a certain amount of moisture in it. With that in mind, a safer approach is to simply allow the moisture to escape. Lime is also alkaline and anti microbial. If anyone is interested in Diaphonite or other insulating Lime plasters, I would recommend contacting Carrington Lime in Gloucestershire who run practical and online courses/seminars on the specific products.
Interesting video as I’m currently looking into this for my own house. I have used a product called superquilt in the past on other building projects, and it’s very effective.
Not only does it provide a lay of insulation it is also a vapour barrier. You just have to make sure you tape the perimeter and overlap with silver tape. You simply batten your walls and counter batten over the top. Seems to be the best product to stop any cold bridging.
I thought I’d share this with you
Thanks Craig, that's interesting. I have a wall on the south side that can't be insulated with anything too thick due to a doorway that's already tight so I'll put that into the mix 👊
VERY GOOD CHARLIE YOU IDENTIFY ISSUES & THEN RESOLVE THEM YOUR BEST BET IS YOURSELF I THINK YOU ARE A PROBLEM SOLVER, DISREGARD ALL ARMCHAIR GENERALS. REGARDS TOM😊
Hey Charlie, I haven't watched it all but there are a lot of options to insulate with lime whilst still maintaining a vapour open construction. There are cork insulated plasters which can give a good u value, also wood fibre with lime plaster would be vapour open too.
This is a far better option IMO. Insulating breathable lime render directly onto the masonry. Vapor barriers and whatnot to keep internal moisture out of the space between the plasterboard and the masonry are never going to be truly airtight and therefore moisture in the air WILL find its way behind at some point.
Great video Charlie. I'd definitely install an MVHR system if you can. I renovated a 1790 farmhouse in the French Alps, wanted to expose the stones but Mairie insisted on render so I insulated outside with Kingspan K5, (fireproof) and rendered over that, then lime plastered inside, external walls, plus lime wash paint. Dug down, underpinned and insulated the foundations, dug down rafted concrete floors on 300mm foamglas gravel then underfloor heated everything. The house is at 1100m, it's about 250m2 and costs about £1500 year to heat and DHW.. where the temp is -5 to -15 for appx 3.5 months whilst house is 22°.
I'm a sparky but did the design, planning and work myself.
Took a while mind you !
Love the channel....
Thanks for that mate. Wow, what a project!! Sounds similar to what I'm having to do right now with foundations missing on a corner of the kitchen. I've decided to go with breathable insulation inside now, given the exterior render isn't breathable. Also lowering the outside ground which will help damp issues on the walls.
@@CharlieDIYte sounds good, lower the ground and try and incorporate as much land drainage as possible. I like those humidity monitors your have, An MVHR will give you a finely controllable tool to manage humidity and hopefully stop any potential condensation before it starts.
@@CharlieDIYte Hi Charlie. I have the exact same problem as you, tyrolene render on the outside, solid walls. What types on breathable materials did you insulate with? In what order and method did you install them? Thanks
The lime plasterers will hate you , but as somebody who wants a warm family house think you doing a sensible and well researched refurb .
Thanks Philip. Yes they will! Oh well, warm house here we come. 😉
I have implemented external insulation along with mechanical ventilation with heat recovery (MVHR) in my home. While it may not strictly adhere to vacuum requirements for MVHR, this combination has proven highly effective. The system functions like a charm, preventing condensation within the house and maintaining significantly lower humidity levels. This integration has successfully created a more comfortable indoor environment, showcasing the practical benefits of combining insulation and mechanical ventilation for improved humidity control.
Hello, what is MVHR brand you got installed? cost of installation? Does it work in conjunction with air source heat pump and under floor heating? thanks for the enlightenment.
I would have dabbed 50mm PIR to the walls and foil taped the joints, then mechanically fix the boards to the wall with plastic 10mm board fixers. That way you’ll get the walls nice and straight. Next, I’d have fixed the plasterboard to the surface of the PIR with expanding foam adhesive. Soudal do a great glue and very easy to use. I never buy insulated plasterboard as it’s twice the price. Battening a wall creates a cold bridge.
In our solid walled home I sealed round the edges of whole sheets of foil backed PIR (celotex etc) with silicone and put that directly onto the plastered wall. Then fix 50x25 tile battens over this to mechanically fix the boards to the wall foil tape the joints then fix the plasterboard to the battens. Gives a nice 25mm warm void behind the plasterboard for the sockets etc with no interruption to the vapour barrier. The whole wall is completely covered with insulation no battens in the way. Also no chance of the battens rotting as all on the warm side of the insulation. Would say the walls are almost air tight in theory.
Life of silicone?
@@asilver2889 more of a belt and braces thing to help with airtightness between the board and the wall. The boards are squashed so tightly to the wall by the mechanically fixed battens I very much doubt any moisture that might find it’s way past a failed bit of silicone in 20 odd years will cause much of a problem.
When doing my bedroom i battened the walls and as the walls were so uneven i used plastic shims to bring them off the wall then used a closed cell expanding foam sprayed behind the battens to stop them flexing, reduce sound and act as the damp proof membrane. I trimmed back any spill out the side of the battens with an old saw then filled between with mineral wool insulation. Then went over all this with my vapour barrier and plasterboard.
That's an absolutely top job. Great work. Yes I've considered rock wool. It means having to install an additional vapour barrier as you say but it's not totally off the table right now. 👊
what size battens did you use? did you go for 100mm. or a smaller size and compress the mineral wool in
Excellent Information Charlie,
It’s a cost that you have to be prepared to lose some floor space to gain comfort as well as peace that your property is not rotting away behind the seems.
I’ve no problem with loosing some floor space to do this but like everything else in life,,,,, Quality comes at a cost.
Thank you so much for sharing, it a great reference video that I’m going to share with a lot of folks.
👍
Does the foil go to the outside or inside with gyproc , if inside wouldn't that cause damp on the outside to seep through the gyproc ? , I have lathing plaster and would like to strip plaster out and replace with foil backed gyproc on to battens with foil to face outside in kitchen with foil insulating sheets on to the gyproc then kitchen cupboards on to that , without the moisture issue it would be easy lol
I've just insulated a north-facing kitchen wall using 4mm cork roll, bonded, full contact, with tile cement (diluted 1+5/PVA+tile cement), to the existing plaster/wall. (The wall is a cavity wall). Hopefully this will mean there's no void to collect moisture. The result so far is signicantly reduced condensation, with a marked increase in temperature of the room. The cork was treated both sides with a diluted PVA 'wash' prior to application, to help with cement bonding. Is working for me!
Well thought out.
Besides basic logic and research specific materials a great plan.
Allow me to share a moisture battle of my own. (not applicable for a problem like yours)
As you know I own a lot of garages and one of them had a half brick wall and with heavy rainfall for a long time at a time moisture came through the wall.
What I did was, I gave the outside a special invisible impregnated coating, throwing water at it will make it drop on the ground or stick at the wall as drops.
Inside I used two component basement coating, once mixed you need to apply it within 40 minutes and it looked like there was a plastic on the wall.
Since it still was a cold wall I made a wooden framework and in between I glued polystyrene foam boards against the wall, a tiny thinner than the wooden framework so there is some air between the polystyrene and the wooden panels.
Made two holes in the wall, front and back of the garage, with air vents, problem solved.
That two component basement coating is so good, it really seals off any moisture coming through the wall.
There is no heating in the garage so this was the best solution and no mould.
Success with the walls, keep us informed !
Not sure if you have it in UK but in NZ theres this product called Crystal, its a non decorative coating you paint/roll/spray onto concrete. The crytals in it actively seek out moisture in the concrete and it becomes a complete waterproof sealer. Typically used in existing subfloor basement concrete walls.
Thanks, that's really interesting. If nothing else could be really useful for the bricks below the dpc. A quick Google suggests we don't have it here though ..
@@CharlieDIYte bit lazy of me its called Crystal Proof. I believe theres many brands that make a similar thing but here its made by Cemix which is probably an Australian company. I believe most local concrete workers probably know the equivalent in UK?
Sounds like some of the tanking systems used here.
We have something similar in Romania, but we call it glass water. You apply with a brush and roller and make the wall 100% waterproof and block water infiltration from outside to inside
I don't know if I was overkill or not, but I built a stud wall 50mm from a granite wall with 100mm deep timber. I then put Kingspan pir 100mm with gapo tape. Where the sockets are I put two noggins directly above and below the box, and a bit of ply out the back and expanding foam to fill.
Then I put a green vapour barrier up, and plaster board ontop, and got a plasterer in. I then used a vinyl mat paint as I hope it will block vapour also, but for me the 50mm out the back provides a ton of ventilation from the attic.
Let me know if anyone can see anything wrong with the setup as I have all the other bedrooms to do this summer!
Great video Charlie.
I've just done similar but pretty much made all the mistake that can be made. Dot and dab'd PIR board to solid stone walls then thought about fitting pattresses afterwards. Lessons learnt and this is the first room so won't be making those mistakes again.
Philip I was the same with the K118 upstairs. Keep an eye on my channel was I'm attending a 2.30 hr training course today with one of the leading breathable insulation providers. I'm be doing an update video on it soon 🔜 👊
That was an interesting video. Only thing i would add to that spec' is a sheet of 11mm OSB behind the plaster board. Not that it will have any meaningful affect on either vapour or heat control, but it makes fixing things (shelves for example) easier. Nothing worse than trying to fix a 500mm wide wall cupboard that isn't widen enough to span between the studs or is wanted in a position that won't coordinate with the studs. Apart from that, i am with your design rationale all the way!
Thanks Nick. That's a decent shout. I was going to install patresses wherever I'm fixing units etc but OSB sheets would future proof things.
If you get any kind of penetrating damp from the outside you can still get mould issues, I worked for a guy who wanted his whole house done with insulated plasterboard dabbed onto the walls it was in an area with a natural spring and sometimes a high water level so I advised him against it but he insisted the walls were dry so I did what he asked only to find that he got mould spores behind the plasterboards.
What people and companies forget is you only need a small bit of mould that will spread and spread even with intermittent damp.
Charlie you don't say whether you intend to treat the mould before insulating? Or indeed whether it matters? Great video.
Yes I'll definitely get rid of the mould Fred. I'll probably spray it with a bleach solution or something like Zinsser Mould Remover, assuming I don't hack off the render entirely.
I'm of the opinion that voids will always have some amount of air 'leakage' into them no matter how much foil tape and we'll made the walls are. And then you've got damp air trapped in a void with a cold wall for the moisture to condense on and with very little way for it to evaporate (after all, you've just spent lots of time foil taping it etc to try keep it out in the first place). Which is gonna lead to mold growth on the wall.
It's a similar debate that the Diy campervan community has, spray foam vs wool, with a void between the insulation and the vans body skin to let it breath? Or let the insulation touch it and risk having it rust.
I honestly can't think of a good solution and I've been thinking about this for 2 years now. Good luck I look forward to am update
I agree nothing's ideal with solid brick walls. Thanks for the comment though 👊
The difference between a camper van and a solid wall though is when moisture condenses on a solid wall it will be wicked out towards the outside of the house where it will evaporate, that’s how old houses were designed to work, assisted by well breathing lime mortars. Until someone cement renders the wall, restricting the escape route for the moisture.
I live in a 200+ year old stone wall property was completely gutted and renovated in the late 60s. The walls were covered in some sort of bitumen, then a stud wall that doesn't touch the stone was put up, and covered with 3cm thick foil backed plasterboard. I was able to learn all this using an inspection camera when fitting shelves. It seems to work fairly well, although the walls are about 50-60cm thick from outside to inside.
Tanking,do the same in basements
Thanks for the update Charlie, hope your kitchen walls will be sorted soon….take care
Another excellent, simply explained, and highly informative video
Thanks Andrew. I'm still researching this insulation issue as I find it fascinating just how complicated it is/ difficult it is to get right. I feel I slightly skirted over the breathable options so I'll try and do another video with my findings.
Hi Charlie, you say using lime plaster wouldn't be warm, however I see other breathable materials on the market like Diathonite Thermactive, which is lime based plaster but has a thermal conductivity of 0.037 W/mK, which although performs only half-decent when compared to something like Kingspan option, but it wouldn't require the void, meaning actually you could add a thicker layer, which then starts matching the Kingspan! On top of that I see that other options like Wood Fibre or simple sheep wool also have thermal conductivity of ~0.038 W/mK, which likely would make this a simpler project and cheaper. I haven't calculated the difference in cost, but I dare to say it would make it a lot less complex and potentially less risky? What is you opinion on this?
Came here to post another recommendation for wood fibre insulation. See the YT video 'AECB Conference 2022 - presentation from Steico'.
The problem with lime is the price
Insulation doesn't generate heat. If you need heat then turn on radiators.
@@otofoto no sh*t, but try to heat up an old tenement building without an insulation...
@@montvydasklumbys7584 Now try to heat up it after insulted from inside. As soon as heating is off it cools instantly down. Air alone doesn't hold much heat.
Solid strategy. Only think I might consider is if you’re looking to put cabinets on the wall I would think about using double thick plasterboard and substituting the inner layer with ply behind wall cabinets for strength.
Thanks. Yes I'm thinking of doing this. I'm also just researching all options including breathable to make sure I'm not missing a trick. Will do a video update at some point.
@@CharlieDIYte good point. The issue is trapped moisture rather than moisture per say. I’ll look out for your update 👍🏼
very good video charlie ! i have started thermal boarding my own bedroom which also is a solid wall construction !
What's important to me from this video is you have taken the time to really think about the insulation - which I find hard to do with work consuming my life. Thank you for the research
Thank you very much. I am planning how to insulate a solid brick outdoor shed my wife wants to use for a yoga studio.
This is the follow up video ruclips.net/video/Ou1CjwflZtM/видео.htmlsi=uoDuJremmj5_ZIRb Worth a watch
You are correct in the middle... you should use a breathable insulation like wood fibre a carrier board and then lime render.... it doesnt have to be cold and only use lime render. You shouldnt use a vapour barrier on a solid wall because you will have the exact same issue you are trying to fix.
Thanks. Here's what I actually did ruclips.net/video/Ou1CjwflZtM/видео.htmlsi=J4R-YpbYMRW7a9zD
Well. That was, without doubt, the best vid on insulation I've seen... 👌
Thanks, really appreciate that 👊
I believe, that putting some far infrared panels in for heating or supplemented heating, would be a very hood idea here 👍👍
Really interesting series Charlie. We live in a Grade II listed building, so although I agree with your arguments for going with internal insulation, it isn’t unfortunately an option for us as we’d never get listed buildings approval for the works (and would end up with an unsaleable property if we went ahead without approval). Over the years, gypsum plaster has been used to reskim some walls and damp/mould is a constant issue in these areas (presumably because it’s less permeable than lime plaster). Even with a decent central heating system, log burner and moisture control, getting RH to under 60% is almost impossible. Upshot is that we will be moving and wouldn’t buy a listed building again, sadly there are just too many restrictions which prevent them being suitable for modern living 😢
Thanks Darren. It's sad isn't it how the restrictions on heritage stock make it so difficult to live in. I'm actually researching breathable insulation right now so keep an eye out for the next video. May not go down the PIR route. 😉
Yeah it's criminal that so many listed buildings will eventually be destroyed by the very people supposed to be protecting them, because of imposing some crazy rules. The sad truth, is that it would be wise to stay clear of these buildings.
Aren't you going to get cold-bridging across the timber? That's why you'll see recommendations to use insulated plasterboard as a layer over the top of the battens, as well as insulation between the battens.
I just came to the comments to point this out, cold bridging through the timbers. You could end up with shadowing on the walls. Also, the 1x1 timbers could be omitted if you ensure the PIR between battens is fitted flush with the front face of the battens.
I retrofitted IWI to our solid wall house using a similar technique but created a 30mm ventilated cavity behind the battens, essentially built stud walls internally in front of the brick walls. The house is very comfortable and retains heat well.
Id gyp-line the walls with rubber gromits to reduce cold bridging. Use 75mm insulation on to the gyp-line , tape the insulation amd then board over ot. This ensures that there is an air gap for the brick to breath, but would do what you want
From what I've understood, the best option is to go for least breathable to most breathable (inside to outside), if space allows (which is the main problem in the UK and why we love PIR). So that would typically be a layer of PIR just under the plasterboard which also acts as the VCL if done right. Beyond that, lots of breathable stuff like rockwool. This assures that any moisture that does pass through (which there will always be, screw penetrations, gaps in tape, etc. always assume there are gaps unless airtightness tested) has a sufficient 'gradient' to evaporate and not condense by immediately hitting a brick wall of impermeable material.
I also noticed that in your bedrooms you did a 25mm layer then a 50mm layer over the top. Apparently this is non-advised due to the gradient stuff I mentioned before. You typically want the thinnest layer at the top, and the thickest layers where it is colder, this helps avoid any interstitial condensation.
Last thing I'd say is those metal bracket things you mentioned for the socket boxes? They're duff, IMO. All they do is create nice little bumps on your flat plasterboard when it goes over the metal hooks. Stick to 4x1s for secure anchoring of backboxes.
I battoned and insulated the entirety of a derelict cottage that we bought a year ago. It's very warm now and we're very happy with it.
We went with 80mm xtratherm and used 4x2 for the batons. There was a few mm gap behind the insulation then as well so we didn't bother putting more batons on top because we were tight for room space. Very happy with how it turned out.
I also bought the Gapotape but found it a bit of a nuisance so ended up not using it mostly and just made a jig to cut them all the correct size to fit tight in the batons. Foamed in any gaps with Hermatic expanding foam
This is such a good video! The approach makes complete sense however I wondered if sealing the wall could trap rising damp? Or is rising damp not an issue at this property? I'm not trying to be clever here, I just have a similar challenge ahead and am formulating the plan!
I insulated my garage walls ( 4 inch brick wall ) to turn it into a habitable room I could use , this is the order how I insulated it
1) 25mm pir tight to the wall and foil tape joints
2) 4x2 timber stud wall with 70mm pir in between to allow a gap for wiring to sockets etc
3) vapour barrier stapled to studs
4) 25mm pir over stud wall and tape joints
5) 12.5 mm plaster board
The first 25mm layer of pir was to stop any thermal bridging. I had to put a warm flat roof on the garage so that meant there was no air flow to the brick work unless I put an air brick in top and bottom of the brick wall but that meant I would lose more floor space in the garage, so I put liquid dpm on the walls to stop any moisture coming through the brick from the outside. I also applied liquid dpm on the garage floor and dpm plastic membrane on the garage floor and lapped it up the wall by 500mm . Any comments would be welcome if you think I am going to get problems by doing it this way
Looks like you have sealed both sides of the inside and the wall. If you have single skin brickwork then you can get some wicking in of moisture from the outside and that would stop it but the issue you have is your are effectively trapping the moisture inside. It depends on how much moisture you have in the room and how much ventilation you have. If you had a bathroom/kitchen etc in there then you’ll need some form of extraction and a way to bring in less humid air. It’s done now so I wouldn’t worry about it. Just buy a humidity meter and keep an eye on the levels and if they get excessive then consider a de humidifier or another solution.
@@davideyres955 thanks for your reply , and I agree with you, just keeping my fingers crossed
How much better insulation do you get from a PIR with a lambda value of 0.0022 compared to the standard 0.0037 ? In my country outer walls are getting up 700mm thick on new houses because we need more and more insulation to live up the minimum requirements. I wish there were somewhere you could compare how much more insulation it would take to get the same U value
700mm? Crazy. Insulation doesn't work like that. Doubling insulation doesn't double savings.
@@otofoto Correct and that is the problem in my view. The house becomes very expensive and not much space inside compared to outside. That is why insulation like PIR is potentially interesting. If it is possible to get the house approved for thinner walls then it becomes a better option
@@jwester7009 Better look at silica gel insulation. It is inorganic and non-toxic.
Unfortunately none of insulation for older buildings is economically viable. It never pays off and after 10years there are new codes and again need to change everything.
None of such investments are paid off, pointless.
From Roger Barnes youtube video, "Escape to a French Fishing Port". Roger is an architect and working on an old stone house. To add insulation, he is adding 3cm of clay and hemp to the interior stone walls (sprayed on) and then covering with a lime plaster. You can check out his video, he explains it all (with diagrams) much better than i could.
I've been working on insulated my parents 200 yr old house, which has sold walls (only the ground level) with internal insulating like render. Called like green ultra. Only did this on the external walls. 20 yrs ago builder just dabbed plasterboard all damped over time. Now been removed. Can feel the difference think I got about 50mm of insulation in some areas as walls are not that straight. Bowing in areas trying to get it flat. Can feel the difference. Wouldn't mind getting a thermal camera to see the temp diff between the ground and top floor as top floor is still solid walls. With some plasterboard on some of the rooms.
Thanks for sharing - does look good where you're wanting to stick to lime render. How have you found building it up to 50mm as it looks like 30mm is the recommended max? 👊
@@CharlieDIYte The wall was pissed as a fart and bulging in places. The areas below the window for example the applied layed of insulation is about 25 to 30mm The recommended application is between 10mm to 30mm per coat, cured for a period of time, keyed at some point. After some time has passed another layer may be applied to build up the thickness. Which in my case was about 50mm. Would deff not apply anymore than a inch at a time as it may fall off... Taken a few weeks to get it to where it needed to be and it's almost completely flat now. 3 coats and some areas and 4 in others as i say parts of the wall bow and bulge. It was very easy to mix and apply. Its nothing ive ever used before. Its ever so light yet sticky. Think of it like bonding but its 10% of the weight, wonderful stuff if you want the building to breath. At the moment a small radiator is in that room to help get some warm in that room. The room is maybe 5metres by 4.5 metres with really high ceilings. It now doesn't feel as cold as it was before the insulation. The rad is only a tiny thing single panel single convector. 500mm x 500mm. Deff would recommend this stuff if 1 wants to let the building breath. It's letting the damp get out that has been covered by plasterboard for 25 yrs. 1 wall when I took off the plasterboard was damp to touch. Can see it physically wet. Just soaked my hand. Behind that plasterboard was some sort of square corrugated tar cardboard that I've not seen before. It is still drying out after a yr. Damp patches are appearing. But at least its not going to be moldy.
Internal wall insulation in cold climates (eg UK) is a bad idea full stop. Your building will rot. I know - I've done lots of it. Will only use external insulation in future.
It only works if: 1) You fully seal the inside with a perfect vapour barrier, which is almost impossible in an old building. What do you do about joist ends? And in the space between floors?
2) You have a breathable cavity between your insulation and the original wall. With holes drilled to the outside.
3) You strictly control the humidity inside the house by installing a whole house MVHR system.
4) You make sure you don't insulate too well! There needs to be some heat lost through the external walls to drive the moisture out.
If you do all this it will work and be fine. But it's rare to find tradesmen who will tape every single pinhole, unfortunately over time MVHR systems won't be maintained, roofs will leak into your cavities, and because you've insulated and sealed on the inside, you WON'T BE ABLE TO SEE THE LEAK until it's rotted your whole wall.
As you will will know Charlie internal insulation on a old wall is a risky business and there is no 100% solution to it I feel in my experience counter battern it so that there is an airflow across the wall but you will have to vent it possibly from the outside somehow also use stainless steel screws in wall when battening
And I'm sure you already checked afew different areas on different walls to make sure the bricks weren't used as a fire stop at doors or any openings or not even fire stops just to hold the small dukes we called them ,bits of wood built in to wall centre to fix door frames
Though as I say you I'm sure have thought of anything I could 👍
Have you ever heard of Gypliner ? Or its generic equivalent. It's been around for at least 30 years.
Granted I just flicked through your video but I'm puzzled by your fascination with timber in these circumstances. If you are attaching timbers to such a wall what is your method of keeping the wall plum and straight in a time/motion efficient manner ?
@CharlieDIYte should have a look at this.
Second this. Gypliner type system or a gypliner independent wall lining system would be a much more modern solution. Negates any issues with cold and damp bridging and not much difference in cost compared to timber battens. No shrinkage either so might negate need for the Gappo tape. Could consider installing weep vents in the cavity void for airflow.
Hi . I dont see any update to this video in relation to the method you decided to use to insulate the walls, or have you a link to the update if it exists? thanks
The audio in your videos is a wiiild ride, Charlie!
Nevertheless, thanks for the great content!
Sorry about that, John. Perhaps wasn't wearing the lapel 🎤.
I meant the little 'correction' insert voice overs you do - always gives me a laugh though, don't change!
What is it you put between the batons that are in contact with the wall?
Thank you for this content and being so encouraging to have ongoing communication. I'm hoping to add some insulation to my internal walls but am wary of moisture problems. It's incredible how little good information there is out there when it's really such an important topic, especially given the cost of heating a home currently!
How do you deal with the need for a vent in a room?
Another approach would be to use moisture conducting insulation. Any condensation that happens inside the walls would than wick to the inside and dry off. One would use stuff like cellulose or woodwool as insulation and woodpanels or clay-bricks as inner wall. Since i've heard of this concept I've come to the conclusion that breathable wall materials actually mean moisture wicking materials (it makes no sense being able to breathe throu clay or lime)
Indeed, I've been looking at wood wool insulation like Lime Green Warmshell, a system from Steico and most recently UdiTHERM NF. These allow vapour to move through, and help to contribute to the thermal mass of the room. Admittedly one does need to use vapour-permeable materials all the way through.
Yes Sascha, the term breathable really means 'vapour open' so that moisture vapour, but not air, can make its way through. It should still be airtight, confusingly. Many conflate 'breathability' with ventilation. I was baffled until I did the training and research.
Brilliant work Charlie
I insulated two flats i own as they had had a few mold problems. and i stuck a heat exchanging ventilation system in. One flat was fine but the bloody tenants in the other climbed up into the roof space and disconnected the power to their system as they thought it cost too much to run then a year later they complained about mold returning. what i found ironic was they had put a tumble dryer in the bedroom where it had become moldy as they didnt like going outside in the cold to hang up their washing.
As you say if you keep an eye on the humidity and open windows or use ventilation you can stop it happening but a lot of the time its down to the people in the house trying to seal themselves in that creates problems.
So frustrating when they do that 🤦 You hear about this time and again unfortunately.
So frustrating when they do that 🤦 You hear about this time and again unfortunately.
Very nice job and thought process. 👍
Thanks 👍
I have solid brick wall with no insulation.
I used battens and superquilt insulation.
After battens again then plaster board this gives you a service void for electrics and plumbing.
Also the foil insulation has built in vapour barrier.
I have completed this in three rooms so far and a noticeable difference.
Uses approximately 70mm thickness
Thanks, that's really useful to know 👊
Well done mate
My worry about internal insulation is the outside of the wall freezing and spalling, also 70mm of foam may meet refurb regulations but not net zero.
Charlie, so the process of insulating walls internally seems a lot more complicated than I had anticipated. I have a tiny box room in the corner of the house so it is cold, but I don't want to lose the depth against the walls that you are doing. I don't even really want to lose say 1 inch of insulation + 1/2 inch of plasterboard. So, I am wondering if you have ever heard of any kind of insulation boards that do not have plasterboard over the top and that I could paint over, or even cover with something thinner to give a reasonably smooth surface - something like a reinforced wallpaper. It would be great if the insulation board were impervious to moisture in order to provide a vapour barrier. Maybe they make something like this for use behind tiles in a bathroom. I don't know. Anyway, what I am asking is whether you know of a method of insulating walls that will be as thin as possible, given that I don't really care about a perfect plasterboard finish.
You could check out products like 'Qboard' - which is typically used in bathrooms and can be tiled directly on top of. They offer several thicknesses (4mm - 5cm or so), are fully waterproof and provide some level of insulation (apparently).
I'm not sure you could wallpaper them directly, but I suppose you could plaster then paint / wallpaper.
Will it stop the wall you stick it to from building up moisture? I have no idea at all! Good luck ;)
@@plazmeh999 Thank you very much. That's really helpful - exactly what I was asking for.
Really helpful video. Thanks so much for sharing 👍🏻
You're welcome, thanks for the comment. 👊
Thanks for sharing your process, love your videos. Your focus seems to be on moisture from inside condensing in the cavity. Is there any concern of water from outside coming through? Other than protecting the battens with vertical dpc strips is there nothing else to do there, e.g. no tanking needed? Another thing I worry about are air gaps: I guess air gaps increase insulation effectiveness. But wherever air can flow, moist air can flow, so why not fill air gaps with foam? Just one missed spot tape would let air in no? If the dew point is in the middle of impenetrable foam wouldn't that be better?
As far as I can tell vapour doesn't just spontaneously condense in the middle of materials, even if this is where the dew point occurs, it has to condense on the coldest surface of that layer.
I think Charlie is using an air gap at the back just encase there is any moisture issues with the solid walls then another on the PB side as a service void so he can have ridiculously deep back boxes.
@@Swwils no air gap = no surface
This is a very well done video.
Suppose all well and good if you have the available space to shrink the room by net 120mm per external wall after hacking off the old lime plaster (in my case). My kitchen is 2200mm wide so just not a realistic solution. Chucking up external insulation over period features on a victorian property....the net zero lot can chuff off!
Have a look at Aerogel - you don't need as much thickness with it but it's expensive.
Hi Charlie. Interesting content, as always! You forgot the include a link to the thermal imaging camera - I'd be interested in getting one, if you could share the details of it. Cheers!
Sorry, now added👊
Not wanting to sound too unorthodox, one could simply not attach electrical conduits to the brickwork. Pull up sockets in the kitchen worktop instead and electrical trunking in the floor beneath kitchen cabinetry? Just a thought.
Could certainly do that 👌 I think there are areas where that would be a bit of a pain though.
@CharlieDIYte fair enough. When you mentioned the back boxes interrupting vapour control layer etc it just reminded me of a project I did 10 years back in Muswell Hill. Getting perimeter insulation in between slab and wall is probably the most important aspect of these domestic projects. Making sure the slab doesn't act as a cold bridge etc.
Humble Architect in Salisbury. Cheers
Taking of condensation, I've got an issue with our cellar. The water vapour is very high this year and the cellar is particularly damp ...we can't keep the relative humidity down at all.
Can you get a dehumidifier down there?
Thanks for the info. Useful.
I insulated the exterior with EPS then silicone rendered, couldn’t do internally as would have lost so much room (1740 cottage), moved windows forward, extended barge boards but luckily soffits were big enough, have to say works wonders….
Thanks Nigel. Definitely the best option if you can. 👍
Thanks Nigel. Definitely the best option if you can. That was a lot of work. Fair play to you.. Did you need to get planning for that? 👍
@@CharlieDIYte I built an extension so was part of the planning, but, if the building was already rendered ( like mine was) and your replacing like for like then no I wouldn’t have needed to. Keep up the good work 👍
Thanks
Thanks Matt. Really appreciate that.
From a thermal performance pov you should not leave voids in your structure. I know this goes agains common practice in the UK and it's a more expensive option but walls need to be void free in order to minimise the chance of mould, cold bridging etc. I am not at all suggesting that you stick the rigid insulation to the brick wall. That is wrong and against manufacturer recommendations and will result in issues. You should however fill the void with some form of wool insulation. I have a personal preference but they will all work so maybe go for an economical option. If you are looking for other improvement of the design, maybe also use steel framing rather than timber. It's a bit harder to start and you will need to get a few more tools but the channel allows for insulation to be tucked in and the thermal bridging happens across the thickness of the steel profile which is substantially smaller area than the timber that you use. Also, once you get going, it's faster to build than timber framing.
This likely goes without saying, but make sure that the outside of your solid walls is in a good state. If you have exposed bricks treat those with water repellent (many to choose from). If you have render, you need to ensure there are no cracks as those are ingress points. Lastly, I your slab was poured with insulated perimeter, I think you may be over engineering this whole thing. It's for you to judge but there is a point at which thermal improvements become exponentially more complicated and costly. I get that this is also content generation for your cash cow but ...
edit: I can't believe I forgot this but I used intelligent membranes for a similar project with great success. And yes you can dot and dab over it and you will not get mould (remember to use a primer on top of purple and under the adhesive)
Is there an breathable membrane on the external surface of wall which could be a form of render to prevent potential issues concerning interstitial and surface condensation
Yes there are breathable EWI systems. However you always need a good ventilation strategy when insulating externally but it's a far superior solution. Here's my update vid ruclips.net/video/Ou1CjwflZtM/видео.htmlsi=0Bx9zSMGiKkAi_Vu 👍
Fantastic video. I'm just wondering if it's worth all the effort, e.g. keeping the insulation boards off the wall underneath using the 1x1's, I know you want to have some aeration to combat any condensation, but any moisture in behind should be dealt with my the lime mortar they've used? What about drilling out some holes at a downward angle every metre so as to allow air into the space? The initial mould you saw might've been due to the paint finish and lack of vapur barrier, end of?
Thanks Matthew. Keep an eye on the channel because I'll be doing a update video on this soon. I've gone with a breathable insulation system. 👊
One external wall in my bedroom is only single skin. Its around 200 years old and is a vertical continuation of the "shared" wall of the terrace. The neighbouring house existed first but is only single story, it seems my house was then built some 50 years later and they put in a single skin wall against the neighbour's existing wall and then built it up to two stories. It takes a fair bit of driving rain and is quite exposed making the room very cold. I'm thinking to go the insulated lime plaster route
Have a look at this if you're going down the lime render route. Haven't used it myself but it was recommended by another viewer. www.lime-green.co.uk/products/lime-render/ultra_render
you should really use rockwool as it is breathable i have had same problem dif is i built an internal stud wall 100mm off wall
It would be so much easier. But I think the problem is without a vapour barrier you're going to get condensation on the bricks.
@@CharlieDIYte u put the vapour barrier staple to stud work thrn plasterboard and make air vents in wall so air can circulate which is what i have done and i habe a 100mm gap between wall and stud
Charlie it’s well worth looking into spray cork. I spray for a company called Corksol
what about cold bridging from the wood ?
Hi Charliediy, really appreciate your video very well done. I see the batons represent a significant cold bridge. Did you consider foam glue ? I used foam glue which unlike dot and dab and batons is foam insulation so no bridge and it worked. Still need vapour barrier but again foam glue on phenolic.
My new project we are using breathable Lyme plaster x 3 layers plus final coat of aerogel plaster which for 10mm has same u value as 75mm of PUR board. Phil
i don't get it. the consensus is tat the most appropriate material is lime plaster right? your only issue seems to be, how to get enough energy to heat the rooms? surely its far cheaper to keep your gas boiler and just install solar with additional heat pump. that will easily be enough to toast any roo and the only additional cost is the solar and heat pump . the solar will run the heat pump so no additional energy costs
Subscribed! Thank you for your info!
The moving of the outlets in front of the vapour layer was intersecting, wonder how cumbersome this is to do
Curious why you chose to insulate on the inside rather than the outside?
External obviously better but not practical for me.
Any of these would be an improvement to the dot and dab directly on to a solid ext wall.
Any thoughts on Insulating Lime Putty? Or a hemp/lime render?
Great video Charlie, I have a similar job and this mentioned all of the same concerns that I’ve been wondering about myself (non-continuous vapour barriers, cutting holes out for sockets plumbing etc). I’d be interested in hearing how your installation went and how it’s holding up? Did you use any form of DPM behind the 4x2s or was it not necessary?
Apologies. I’ve just realised you mentioned the DPM already.
Mate, I haven't done it yet and think I'm going to go with a breathable insulation from a company called SWIP. Watch this space...
friends place had been diy insulated internally with thin polystyrene and plasterboard. caused terrible damp problems
Yep, not good. I found polystyrene backed wallpaper here when we moved in.
are you going to go for the green coloured (moisture resistant +£3/sheet) plasterboard, at lower level?
I hadn't got to that point yet but yes I should consider this, albeit with the vapour barrier and the socket boxes allowing moisture through anyway it's probably less important. For £3 a sheet extra it's probably worth it though.
Hi Charlie …. I don’t know if you thought about this … but what about a liquid dpm the stuff I use is like a black tar when it drys it’s like a black sheet .. then I just apply normal plaster board…. Does the treat for damp
Like Bostik bituminous paint? Yes I've considered this particularly for below the damp course.👍
Hi Charlie i have been looking for this advice everywhere thankyou! I am doing similar but my walls have rising damp (solid walls) looks like it has been plastered not lime so hopefully once removed it will subside. im considering using dry rods as a chemical dpc before using said method you are doing any advice would be great?