I've been using instastik for around 12 years, some tips would be to spray the board and wall with water prior to applying the foam, you get greater adhesion, apply foam between the edges of the boards to stop cold bridging. Also a more cost effective way is to use kingspan or similar board, then stick the plaster board to the kingspan. I've gone up-to 100mm kingspan with 15mm megadeco plaster boards. Bathroom walls have a load of around 100kg per 8x4 area that I have done. The key is a light waterspray for bonding and on old walls I use sbr bond on the walls. One last tip would be when sticking the plaster boards is when you butt them up together just twist a plasterboard screw between the sheets every 300-400mm the small amount of hold stops the sheet your sticking from expanding past the previous one and keeps them flush.
I love insta stick it sticks almost anything and goes off quickly it's great for giving skirting etc. We insulated loads of houses for housing associations with 100mm insulation backed plasterboard and fixed it using insta stick with a couple of concrete screws to hold it tight against the existing plaster it was a really good earner. Your meant to return it around the corner something like a minimum of 150mm though it do performs quite well without that. Nice tip advising people to put some foam in the edges btw. 👍😀
@@AliDymock very well, I have over 100kg per 8x4 board all stuck on the foil. The key is a light waterspray to increase the bond. Using kingspan, you get a better U value, less wastage and it's cheaper than a bonded insulation/ plaster board.
Hi I have a plan to buy 20mm pir board two side silver foil (£20/each) and 9.5mm plasterboard (£10/each) then I have a plan to stick them together. Then cost is a half price (£60-65 shop price ) This diy plasterboard I have plan to stick from inside to empty cavity wall ( build in1965 ) What’s your advice, it’s good idea?? Thanks
I seem to be following behind your life experiences in some regards, I used your videos to build my garden room 2 years ago, and when I just searched for 'sticking insulated plasterboard', up you popped with the goods! 😅 Much appreciated, your videos are always well presented, informative and very very helpful.
Great video . I did a whole house like you’ve done here during a refurb. Insta-stik is incredibly strong. You can literally stick almost anything to anything and it’s not coming apart. It’s much quicker and cleaner than board adhesive dot and dab. You can get 2-3 boards from a can so it’s just slightly better value as well. It locks the wall boards to the ceilings, as the Victorian properties have mostly settled out of square and the inevitable gaps can be fully filled and locked together for the plasterer to tape over. No movement cracks later. But you need to bear in mind that the foam will continue to push a bit for quite a few minutes after it’s stuck the board, so care needs to be taken not to get a step against the adjacent board. It looks and smells like low expansion foam but it’s unbelievably strong once it’s cured. It can be tempting to use it where you shouldn’t really. It’s excellent on skirtings and architraves as well. No drilling and filling. Much much better than no-nails.
Yeh it is amazing stuff and it's interesting how the comments have differed vs dot and dab though that is often the case when a newer way of doing things comes about. I think it would be great on skirting but I wouldn't want to be the guy who has to pull the skirting off down the line.
@@AliDymock I’m looking at using your video as a proof of concept to do a couple of walls in our kitchen. Reckon once the mechanical fixings are up, that it’ll be strong enough to hang kitchen cabinets off?
@@Musicman1001 someone in another comment said you'll definitely need mechanical fixings of doing this in a kitchen where cupboards are going to be hung.
Nicely explained, really competent analysis of interstitial condensation and well described. So many other diy dot and dabbers getting this wrong. Congratulations. (Ex architect and lecturer in construction technology)
Great work man, I ended up going the stud wall route using CLS16 and 50mm PIR with a 12.5mm board on. This was on a late 1800's property. I put strips of DPC on every timber that was touching the wall and had an air gap between the wall and insulation (about 10-15mm on average) I was surpised how much noise it actually cut out just by doing this let alone how warm it was.
I'm looking at doing exactly this once I move into my new place and in all my research hadn't seen the foam as an option. Always helpful to see well presented alternatives, thanks!
Snap, but I’d heard it worked and given the paper backing it should be no different to regular foam attached plasterboard. We’ll see though. I’ll update as the room progresses!
Silka plasterboard foam might be an option too, its amazing stuff and the nozzle is really good, ive had left over stuff and used it 2months later no problem, i have a form gun but after lots of use its pretty gunked up now, tried cleaning it but i think its too far gone, so the silka nozzle was a nice surprise.
I've only ever used mechanical fixing on insulated plasterboard, after seeing a job where it had been dot and dabbed with plasterboard adhesive and the plasterboard had later become detached from the polystyrene. I've always used 6mm sds drill, red plugs, then 65mm aluminium nails (which hold in plugs better than you'd imagine.) You have to use a bit of scrim over the nail heads due to the compressibility of the insulation, otherwise the heads may pop occasionally. But I must admit, this looks like a feasible solution that would be a hell of a lot quicker. I'll give it a go next time I have some to do.
Good video! Curious to know if you saw any noticeable benefits since you completed the project a year ago and been through a winter to measure the difference before and after? Thanks , I’m thinking of doing the same .
I come from a construction background, started from the architectural design field up to PM on big jobs. I do alot of DIY at home myself as i have an understanding of how it all goes together considering i would usually specify it on drawings. Im too lazy to document my work but if i did, it would be exactly like this, well done, really like the attention to detail and numbers according to the manufacturer. Subbed.
Welcome to the channel Norman! I’ve always found PMs to be very knowledgeable across a broad range of trades, big picture types but with an eye for detail. I’m only a DIYer so I’m learning and documenting as I go. No calamities so far 🤣🤞
Nice tutorial and analysis. I had damp issues in my Victorian house in the alcoves so built a stud wall with 50mm gap from the wall then celotex insulation and plasterboard. I also vented behind the stud wall with holes in the suspended floor and going up through the ceiling and the same above. I found that I didn't need a plasterer by carefully filling all gaps with caulk then polyfiller to level, cross lining with lining paper and using a top layer of textured paper. If the costs of heating keep going up, I may sacrifice more interior space with another layer of insulated plasterboard!
Interesting video, very good how you give a run down of all the options and your reasoning. I live in a 1930's semi with solid brick walls, a few years ago I internally insulated all the of external walls with battens and 50mm of PIR insulation between in much the same way the walls in your garden room are constructed, and it has made a marked difference in the comfort level of our house as well as the heating costs, which are now significantly lower. It was however, a huge amount of work, especially as we hacked off all of the original lime plaster (it was loose it places anyway) to maximise room space. Keep up the good work!
Sounds like a very solid job. This was a lazy way of doing it and a bit of a test but it’s worked well for now, we’ll see how it fairs before I do the next room 👍
I'm very interested to see whether this is still performing as desired after a couple of years. This is almost exactly what I need to specify for a job I'm working on, so it would definitely be good to know whether it worked out well.
Superb! I found Knauf technical to be really helpful when I was selecting the insulated board for our renovation. They were happy to provide a u-value calc and dew point analysis via email - no fee or anything. Great service.
I did a baton frame of 2x1’’ with 400mm centres with 50mm kingspan filling. Then put a visquin sheet across the whole wall to stop moisture, then plaster board.
Next time you remove a radiator,after screwing down the thermostatic valve fit a blank to the outlet because they have a frost stat in the valve and they can open up if it gets cold and flood the room.
Hi just one thing you should do is around the window , leave the slab over hang beyond the reveals ,then later trim the foam only from the back with a craft knife , cut your slab infill around the window and foam in place when all is dry cut off excess slab around window giving you a slab to slab corner , hope you can follow , important to avoid cold bridge at window reveals 👍
Yep understood definitely the best way to go. The problem I had is that I didn't have room for plasterboard, insulated or otherwise over the plaster and getting the plaster off seemed really difficult (might need to get myself an SDS drill). And then I can see it all being ripped off anyway if/when the windows are replaced. Might try it on the next room though!
You need to pull up (or cut) the floorboards at the wall to be insulated and insulate between the timbers using PIR. The cold bridge on the uninsulated bricks will cause condensation, black mould and potentially rotted floor beams. Rockwool will not help in this situation. You can cut wall the insulation board to a loose fit between the beams and use spray foam to fill the gaps all around. The radiator upstand pipes can be replaced with Hep2O allowing a neat connection without solder. Use an inline stop valve to isolate the pipe under the floor. When the system is depressurised you can make one cut and lose virtually no water. Use a block style cutter and have the valve ready to quickly push on. Keep a wet vac handy to clean up spills but you probably wont need it.
I agree with the fact that there are a lot of cowboys on the market just wanting to scavenge on government subsidies for insulating your house. A thorough bit of research is needed and will pay off if you're going to hire someone to do the job for you. I'm planning to have my exterior walls insulated from the outside and rendered, this is a real specialist job and I chose to go with a builder which already has 20+ years of experience with the process and offers 20 years of guarantee on his work! So worth the extra bit of money. The other companies which were invited to make an offer trough one of these websites were you can get 5 offers didn't even reply back, so they probably considered the job as too complicated for them because of some technical details of the house. Another advantage of the chosen builder is that he can do some structural changes on supporting walls at the same time, so it isn't necessary to have two different companies having to work in each way or at different times. But as for the easier jobs, I agree on the fact that getting the government subsidy does not cover the added cost for labour when outsourcing, as one of the requirements is that the job must be done by a certified company, so you're still saving money when doing it yourself without getting the subsidy.
Hi i like the video however its a myth externally insulated buildings dont suffer with this problem. Consider the scenario. Cold house, You return home on a cold day and put the heating on. You increase the temp & humidity in the home but the thermal mass of the wall is slow to respond and lags behind the room temp. The moisture enters the fabric due to higher humidity internally compared to outside and as the thermal mass mass of the wall is slow to respond Dewpoint occurs instantly on the inside of the wall. Moisture migrates through the fabric and becomes trapped behind the external insulation.. Bad bad bad bad. Only mitigation against this is a mechanical ventilation unit to combat the humidity rise. Internally insulated walls respond quickly with the rapid temperature change and do not lag behind the internal temp. Most insulations used for this have low permeability and and moisture going beyond the insulation is minimal. Also with the external structure not wrapped in external insulation, the building will eventually permeate the moisture to atmosphere instead of being trapped. This is why timber frame buildings use an internal vcl eg polythene and external vapour control layer which allows moist to escape to atmosphere . The other way around would be a total distater. Spent 13 yrs testing /investigating building defects, air leakage testing. Cavity filled and externally wrapped solid wall buildings are something that keeps cropping up...
Wow fantastic comment esp. with all that experience behind you. It does make sense what you say but I'd have thought that even with the heating off for the day the external insulation would keep the brick walls reasonably warm, certainly more than uninsulated walls but the point about moisture getting trapped outside of the wall but inside of the insulation makes total sense but again, will it condense? I've been hearing about issues with cavity walls so let's say you were doing a brick/block extension, how would you build the external walls - internally insulated?
Any update on how this has worked? I thought it was best practice to take up the flooring and have the insulated board go all the way down to the top of the ceiling below, you have left a big gap under the floor board area so would be nice to know what its been like 1 year down the road... Cheers
One problem you can get doing this is before you put insulated boards on you can see if you have water or damp coming through the walls but once you have stuck insulated plasterboards on you will never know and in those cases you can get black mould form behind the insulated plasterboard. If your pointing outside is all good you may be fine but if it’s a single 9 inch brick wall you may get penetrating damp, if the wall has a cavity you should be fine unless the cavity is bridged anywhere, remember black mould is a living organism and you only need a small patch and soon the whole back of the boards will be covered.
From my experience i would not use dob n dab on foil faced pir foam backed plasterboard as the adhesion between the foil face and the dob n dab mixture may seem sufficient initially i have found that it will separate after a short period of time.
A good trick to not create a visible butt joint if you can’t fit a full board in a space, instead of fully cutting in half you can score the back side and snap the plasterboard, leaving the front paper intact. Works well with normal plasterboard, maybe some sealant in the back where the cut was in this one could work
Did this to our Victorian bedroom a few months ago! I had a few added complications, namely having to replace all the double glazing and dealing with a bay window. Cutting that insulated plasterboard at a perfect angle is quite the challenge! Otherwise you did pretty much the same as me. Great work.
Sounds like it's holding up nicely. I have a half-hexagon bay window downstairs and was wondering how easy it is cut the angles. God to know it's doable, well done 👍
@@AliDymock I used a digital angle finder to work out roughly the angle to cut. It doesn't help the the original walls, ceiling and floor were all wonky so I needed to use a lot more foam at the bottom to get the boards plumb. Fill any big gaps with more foam to prevent thermal bridging and slap on some bonding to make up any significant gaps.
Good video, our house is a 1934 property with solid brick walls. We had a external wall where the hallway/stair is. The plaster had blown and wall was sweating as you could feel it and almost smell it. We removed all plaster back to brick and allowed the wall to breathe and dry out. After a few month we got to work but only had a depth of 35mmish to use where no suitable insulated board product would suffice. After some research we applied a tanking slurry, a render mix and floated finishing plaster on top. Wall is dry as a bone now and no longer that cold to touch wall... but videos and knowledge is needed on the subject as there is so much conflicting info!
Good video. How did you prevent moisture migrating and condensing around the wooden beams? I'm doing a similar job but I'm afraid that the wood in the walls will rot because of this excessive moisture.
If you had removed the plaster board on the front wall would that have saved you a significant thickness? Thank you for a superb and very clear description.
Hi,just wondering how your getting on with the insulated plasterboard,if you’ve had any issues and if it made a difference with keeping your house warm?
Good tip with emptying the rad. Just a note re cavity insulation from the 80 ( and 90 and even into the early 00s) only a lawyer of about 50 mm would likely have been added, still leaving a 50mm cavity which can still be filled to greatly improved the overall insulation. The cavity insulation would originally have been installed by the block/brick layers and could often have been poorly done as they would have been working around wall ties which caused gaps. The insulation would also have been low density polystyrene.
Did you check the vapour resistance of the boards you used? Depending on the thermal value of the construction it may not be enough to stop condensation, lots of these insulated boards claim water vapour control even though they have quite poor water vapour performance or no dedicated vapour control layer at all - general suppliers also tend to get this mixed up.
@@Swwils thank you. I could only find these in polystyrene version, not PIR. I see other vendors have vapour barriers that are to build regs standards e.g. Recticel supply a PIR / plasterboard with vapour barrier (Eurothane PL) that conforms to EN ISO 10456. Have you come across these?
@@jve You just need to make sure that you are actually getting what you need, there are two main vapour resistance values used so it can be quite confusing. Your supplier might not know the difference - if in doubt contact the manufacturers technical team directly, they will be of massive help. You'll see typical boards like XPS that has no vapour control layer with a resistance like 12.8 MNs/g or even the regular thermal laminate that has no resistance at all but then ones with vapour control layers will be around 80 to 150 MNs/g like PIR laminate.
@@AliDymock I fixed a door frame to a stone wall with expanding foam and saw later it had bent the vertical sides inwards. By way of a blokey aside we came across the "two part mix" for making expanding foam and so filled a hard plastic barrel, screwed down the top and 2 minutes later nearly got blasted off the earth by a fantastic explosion! Covered in it.. hair clothes the lot! Amazing!!
@@deanoh6414 an important detail that should be emphasised. Some insulation is expanded polystyrene and I have a feeling that expanding adhesive-foam might disolve it.
Great video, i done this throughout the house all external walls last year using kingspan plasterboard sheets. I Would recommend soudal plasterboard adhesive, great stuff, then big twist headed helical fixings.
Great tip! And I love Soudal foam, defo worth the extra few £s over the No Nonsense stuff. I didn't know they did a plasterboard adhesive type foam though. Good shout on the fixings, my one regret on this.
Warning, if there's a chance that the room temperature will drop below, I think, 5C just closing down the TRV is not enough as they open at about this temperature as a built in anti-frost setting. Use a proper screw on valve depressor thingy, they usually come with the TRV. Been there done that, didn't enjoy the soaked floor experience! Secondly, I think the insulation on all these insulated boards acts as a vapour barrier.
I build a sun room 7 years ago 6m by 5m,,windows on 2 sides and 2 sky lights (velux window) i have 300mmcavity walls , i got them pumped with insulation , and on the inside walls i put insulated plasterboard 12mm plasterboard with 35mm insulation, its very warm with one rad about 1.5 m long under a window and on on the wall about 300 mm wide and 1.5 m tall, the roof is a warm roof, worth every penny, and looks good too... great video man
@@AliDymock yes,lots of glass but , i put on extra long eaves, i picked it up while working in Austratia, it works there , so why noy try it here, im in the Rep of Ireland. the sunny southeast,,;-) the sky windows are on a remote and close if it rains , very handy
Being a solid wall from the 1920’s have you got lime mortar solid walls? We’re looking to internally insulate our 1890’s cottage but been advised repeatedly by preservation companies not to use gypsum plasterboard or create a vapour barrier on the external solid walls. We’ve been told the solid walls need to breath. Going with a wood fibre board and a lime plaster finish to avoid any damp issues later. Really interested to see how the insulated plasterboard works out for you. Cheers for the video.
I think you are generally ok with gypsum if you have a damp proof course thus helping the wall above it to stay dry. In old buildings with no dpc the walls can contain considerably more moisture and need to breathe, lime plaster allows this while gyp doesn't. Also consider the paint over the plaster as this will need to be permeable as well and lots of modern paints aren't. Full disclosure I'm not an expert.
I have been advised the same solid wall needs to breathe. I thought of why not use good roofing membrane on the solid brick wall which is breathable and acts as a water vapour barrier on the wall then batten up and use rockwool (insulated and breathable) Inbetween then use moisture plasterboard used for bathrooms?
While floor up, should have spayed the joists ends with anti-rot /wood worm. Because the insulation you used between the joists is less air tight than that above this becomes a cold bridge. Any moisture under the floor will condence on the outside wall. Spay would extend the joists life by 20 years ish. You mentioned possible use of polystyrene. NO. In the event of a fire this will kill you quicker than what you have used. Also moving forward, if you ever needed to rent the place out, polystyrene is simply not allowed.
Do not take radiators off like this, you'll get lucky a few times but the valves can come off especially in older houses. Always hold the valve steady with a pair of grips whilst unscrewing the radiator.
Nice job, but get ready to have mould start growing where you've used uncovered metal fixings at 11:49. The warm air will condense on the cold screw head and you'll have a lovely grey patch to keep wiping clean during the winter.
Hi Ali, thanks for a great video. Can I ask, if you are getting a new EPC certificate for this house, do they check if it's done by a certified installer or do they accept DIY jobs and presume it's installed as per product manual? Thanks
I've read that moisture can travel from outside inwards through the wall. Is this something you considered? I think there are special coatings that can be painted on to the exterior which will stop water getting in but allow moisture to escape. Thanks for the video :)
Just a note of caution. What ever you do to improve the thermal efficiency of your property. Please remember when getting an Energy Performance certificate for your property, improvements need to be evidenced either visually or with specific documentation. When it comes to DIY, this may prove difficult.
Tape and jointing not be too easy when butjoints and not tapered joins However you can get fiba tape ultra thin which will help. A wallpaper would also. The top range insulation lining paper and ready mix glue is a pretty good budget option its £100 a 1m wide roll. It does work to an extent. Used in own property.
Yeh I've done it before and just had to feather the butt joints a lot, it came out well. I used paper tape, didn't know about an ultra thin mesh - thanks!
I don't see how this is a continuous vapour barrier if the foil is on the back and the acoustic sealer is on the front, with a porous material and the thin air gap of the crack where panels abut between the two airtight elements. I may be missing something though. Thanks for sharing your experience as always.
Such a useful vid, thanks Ali. Anyone see any issues with tiling over this type of system? with the extra fixings it should be plenty strong enough for a grout and tile finish in a bathroom right?
id be really concerned about creating damp between the cold brick wall and the insulation. You mention that we create a lot of damp in the internal atmosphere of the house with cooking and showering etc, i'd consider a MVHR (mechanical ventilation with heat recovery) system to try to keep the internal moisture levels to a minimum. I'd be interested to see what this was like in a year or so and to see if you do indeed end up with damp or rotting joists. Check out Peter Ward on youtube, he is an expert on damp in old solid wall buildings. Scary stuff damp.
I agree with the choice of insulted plasterboard just not a fan of sticking it as a fixing, you can get fixings especially for insulated boards that give a much better fix
@@AliDymock don’t usually buy them on amazon but these are the closest to the ones I buy at our local building merchants, just drill a hole and hammer them in. The take a great fix
Could you stick on acoustic boards using the foam and would it work to deaden the sound more than drywall adhesive or fixings? Possibly 2 layers of acoustic plasterboard?
Hi Ali. I'm looking to do this in the next few months. Can I hide a gas pipe in the insulation,by cutting a channel out the back of a panel. Great video. 👍
Hi check the plumb of your walls first and indeed how straight the existing wall runs because it may interfere with your boarding and it’s a real pain to have to undo your work because you realise there is an issue that stops you achieving a plumb flat wall
Do you have a video of adding insulated board to a bay window? Mine has ancient expanded poly tiles over the insides of the solid stone window mullions. This looks terrible and the joints/gaps encourage mould. However Im not sure how to mitre the boards to fit?
I Want to do this in my daughter’s room. I have a couple of questions if hats ok. 1) Do you only need to do the outer walls? I was planning on doing all 4 internal walls in her room but if I don’t need to then i can save money! 2) I saw on another video about foam insulation where they advised to have a gap between the insulation and the wall to prevent condensation. (I’m going to have to take the plaster off as it’s in a mess) is it safe to stick it straight onto the brickwork without a gap? Thank you
I'd like to do this in my bathroom and apply over existing plaster which has been painted. Would it be best to remove the existing paint before installing the thermal plasterboard?
9:14 Just a tip for the future. You could have left the corner on and cut it off after installation with an old saw, just cut in line with the opening. Or hold it and cut along the window before installing. Saves all the measuring and marking.
Not going to lie, when I first saw you doing DIY in pyjamas and flip flops, I thought what the hell!? However as the video progressed I realised it was you (outside building guy) lol good informative vid 👍🏼 P.S Any update on the heating bills situation?
0:00 Intro
0:17 Prep work
2:45 Solid vs Cavity Walls
3:54 Internal vs External insulation
5:26 Options for Internal Insulation
7:01 Building Regs & U-value
8:12 Options for Attaching Insulated Plasterboard
8:42 Attaching with Insta-Stik Foam
11:26 Mechanical fixings
11:56 Window Reveals
12:30 Finishing Touches
13:04 Outro
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I've been using instastik for around 12 years, some tips would be to spray the board and wall with water prior to applying the foam, you get greater adhesion, apply foam between the edges of the boards to stop cold bridging. Also a more cost effective way is to use kingspan or similar board, then stick the plaster board to the kingspan. I've gone up-to 100mm kingspan with 15mm megadeco plaster boards. Bathroom walls have a load of around 100kg per 8x4 area that I have done. The key is a light waterspray for bonding and on old walls I use sbr bond on the walls. One last tip would be when sticking the plaster boards is when you butt them up together just twist a plasterboard screw between the sheets every 300-400mm the small amount of hold stops the sheet your sticking from expanding past the previous one and keeps them flush.
I love insta stick it sticks almost anything and goes off quickly it's great for giving skirting etc. We insulated loads of houses for housing associations with 100mm insulation backed plasterboard and fixed it using insta stick with a couple of concrete screws to hold it tight against the existing plaster it was a really good earner. Your meant to return it around the corner something like a minimum of 150mm though it do performs quite well without that. Nice tip advising people to put some foam in the edges btw. 👍😀
Good stuff Kevin. How well does Insta Stik stick to foil would you say?
I wouldn't want to be the guy who has to pull off the skirting down the line! It's amazing how strong it is!
@@AliDymock very well, I have over 100kg per 8x4 board all stuck on the foil. The key is a light waterspray to increase the bond. Using kingspan, you get a better U value, less wastage and it's cheaper than a bonded insulation/ plaster board.
Hi
I have a plan to buy 20mm pir board two side silver foil (£20/each) and 9.5mm plasterboard (£10/each) then I have a plan to stick them together. Then cost is a half price (£60-65 shop price )
This diy plasterboard I have plan to stick from inside to empty cavity wall ( build in1965 )
What’s your advice, it’s good idea??
Thanks
I seem to be following behind your life experiences in some regards, I used your videos to build my garden room 2 years ago, and when I just searched for 'sticking insulated plasterboard', up you popped with the goods! 😅
Much appreciated, your videos are always well presented, informative and very very helpful.
Great video . I did a whole house like you’ve done here during a refurb. Insta-stik is incredibly strong. You can literally stick almost anything to anything and it’s not coming apart. It’s much quicker and cleaner than board adhesive dot and dab. You can get 2-3 boards from a can so it’s just slightly better value as well. It locks the wall boards to the ceilings, as the Victorian properties have mostly settled out of square and the inevitable gaps can be fully filled and locked together for the plasterer to tape over. No movement cracks later. But you need to bear in mind that the foam will continue to push a bit for quite a few minutes after it’s stuck the board, so care needs to be taken not to get a step against the adjacent board. It looks and smells like low expansion foam but it’s unbelievably strong once it’s cured. It can be tempting to use it where you shouldn’t really. It’s excellent on skirtings and architraves as well. No drilling and filling. Much much better than no-nails.
Yeh it is amazing stuff and it's interesting how the comments have differed vs dot and dab though that is often the case when a newer way of doing things comes about. I think it would be great on skirting but I wouldn't want to be the guy who has to pull the skirting off down the line.
@@AliDymock I’m looking at using your video as a proof of concept to do a couple of walls in our kitchen. Reckon once the mechanical fixings are up, that it’ll be strong enough to hang kitchen cabinets off?
@@Musicman1001 someone in another comment said you'll definitely need mechanical fixings of doing this in a kitchen where cupboards are going to be hung.
Nicely explained, really competent analysis of interstitial condensation and well described. So many other diy dot and dabbers getting this wrong. Congratulations. (Ex architect and lecturer in construction technology)
Great work man, I ended up going the stud wall route using CLS16 and 50mm PIR with a 12.5mm board on. This was on a late 1800's property. I put strips of DPC on every timber that was touching the wall and had an air gap between the wall and insulation (about 10-15mm on average)
I was surpised how much noise it actually cut out just by doing this let alone how warm it was.
You could also use minimal gap expansion foam between the timbers to prevent cold bridging and eventual decay.
I'm looking at doing exactly this once I move into my new place and in all my research hadn't seen the foam as an option. Always helpful to see well presented alternatives, thanks!
Snap, but I’d heard it worked and given the paper backing it should be no different to regular foam attached plasterboard. We’ll see though. I’ll update as the room progresses!
Silka plasterboard foam might be an option too, its amazing stuff and the nozzle is really good, ive had left over stuff and used it 2months later no problem, i have a form gun but after lots of use its pretty gunked up now, tried cleaning it but i think its too far gone, so the silka nozzle was a nice surprise.
I've only ever used mechanical fixing on insulated plasterboard, after seeing a job where it had been dot and dabbed with plasterboard adhesive and the plasterboard had later become detached from the polystyrene. I've always used 6mm sds drill, red plugs, then 65mm aluminium nails (which hold in plugs better than you'd imagine.) You have to use a bit of scrim over the nail heads due to the compressibility of the insulation, otherwise the heads may pop occasionally. But I must admit, this looks like a feasible solution that would be a hell of a lot quicker. I'll give it a go next time I have some to do.
Good video! Curious to know if you saw any noticeable benefits since you completed the project a year ago and been through a winter to measure the difference before and after? Thanks , I’m thinking of doing the same .
I come from a construction background, started from the architectural design field up to PM on big jobs. I do alot of DIY at home myself as i have an understanding of how it all goes together considering i would usually specify it on drawings. Im too lazy to document my work but if i did, it would be exactly like this, well done, really like the attention to detail and numbers according to the manufacturer. Subbed.
Welcome to the channel Norman! I’ve always found PMs to be very knowledgeable across a broad range of trades, big picture types but with an eye for detail. I’m only a DIYer so I’m learning and documenting as I go. No calamities so far 🤣🤞
Love the upgrade to flip flops when you might step on a gripper rod or staple 🤣
😆 I should probably set a better example...
Nice tutorial and analysis. I had damp issues in my Victorian house in the alcoves so built a stud wall with 50mm gap from the wall then celotex insulation and plasterboard. I also vented behind the stud wall with holes in the suspended floor and going up through the ceiling and the same above. I found that I didn't need a plasterer by carefully filling all gaps with caulk then polyfiller to level, cross lining with lining paper and using a top layer of textured paper. If the costs of heating keep going up, I may sacrifice more interior space with another layer of insulated plasterboard!
Interesting video, very good how you give a run down of all the options and your reasoning.
I live in a 1930's semi with solid brick walls, a few years ago I internally insulated all the of external walls with battens and 50mm of PIR insulation between in much the same way the walls in your garden room are constructed, and it has made a marked difference in the comfort level of our house as well as the heating costs, which are now significantly lower. It was however, a huge amount of work, especially as we hacked off all of the original lime plaster (it was loose it places anyway) to maximise room space.
Keep up the good work!
Sounds like a very solid job. This was a lazy way of doing it and a bit of a test but it’s worked well for now, we’ll see how it fairs before I do the next room 👍
I'm very interested to see whether this is still performing as desired after a couple of years. This is almost exactly what I need to specify for a job I'm working on, so it would definitely be good to know whether it worked out well.
Superb!
I found Knauf technical to be really helpful when I was selecting the insulated board for our renovation. They were happy to provide a u-value calc and dew point analysis via email - no fee or anything. Great service.
Shame that knaufs full range is really hard to get ahold of in the UK!
I did a baton frame of 2x1’’ with 400mm centres with 50mm kingspan filling. Then put a visquin sheet across the whole wall to stop moisture, then plaster board.
Amazing. Two videos that will be of great interest as in the coming months as i have both these jobs to do. 👍🏻
Great stuff John!
Next time you remove a radiator,after screwing down the thermostatic valve fit a blank to the outlet because they have a frost stat in the valve and they can open up if it gets cold and flood the room.
Thanks Barry, did not know that!
To make a blank, rap some ptfe tape round 5p piece. Place inside a nut and screw on to valve body.
Hi just one thing you should do is around the window , leave the slab over hang beyond the reveals ,then later trim the foam only from the back with a craft knife , cut your slab infill around the window and foam in place when all is dry cut off excess slab around window giving you a slab to slab corner , hope you can follow , important to avoid cold bridge at window reveals 👍
Yep understood definitely the best way to go. The problem I had is that I didn't have room for plasterboard, insulated or otherwise over the plaster and getting the plaster off seemed really difficult (might need to get myself an SDS drill). And then I can see it all being ripped off anyway if/when the windows are replaced. Might try it on the next room though!
Been using it for over 10 yrs.brilliant stuff
You need to pull up (or cut) the floorboards at the wall to be insulated and insulate between the timbers using PIR. The cold bridge on the uninsulated bricks will cause condensation, black mould and potentially rotted floor beams. Rockwool will not help in this situation. You can cut wall the insulation board to a loose fit between the beams and use spray foam to fill the gaps all around.
The radiator upstand pipes can be replaced with Hep2O allowing a neat connection without solder. Use an inline stop valve to isolate the pipe under the floor. When the system is depressurised you can make one cut and lose virtually no water. Use a block style cutter and have the valve ready to quickly push on. Keep a wet vac handy to clean up spills but you probably wont need it.
Good point. Have you seen mould or rotten floor beams in practice after internally insulating a wall? If so, how long afterwards?
Good video. Precise and to the point.
You're a braver man than I removing that rad!! Great work
Great job. Thank you for the time and effort you took to make this video and share it with us. Greetings from Croatia.
Croatia is lovely, you lucky chap. Glad the vid helped.
You need to use the thermostat vale stop cap. If you simply screw it to zero there's always the risk a bout of cold will open the valve.
Glad to have found more from you after following your Garden Workshop Series!
Great blend of instruction and rationale.
Does foam adhesive reduce air cavities behind the insulation board and thereby reduce amount of condensation/mould?
Great video mate. Very informative and great editing. Well done
Nice job you can always put a washer before hammering in the mechanical fixing
A great, detailed and informative video. Thanks for posting!
I agree with the fact that there are a lot of cowboys on the market just wanting to scavenge on government subsidies for insulating your house.
A thorough bit of research is needed and will pay off if you're going to hire someone to do the job for you.
I'm planning to have my exterior walls insulated from the outside and rendered, this is a real specialist job and I chose to go with a builder which already has 20+ years of experience with the process and offers 20 years of guarantee on his work! So worth the extra bit of money.
The other companies which were invited to make an offer trough one of these websites were you can get 5 offers didn't even reply back, so they probably considered the job as too complicated for them because of some technical details of the house.
Another advantage of the chosen builder is that he can do some structural changes on supporting walls at the same time, so it isn't necessary to have two different companies having to work in each way or at different times.
But as for the easier jobs, I agree on the fact that getting the government subsidy does not cover the added cost for labour when outsourcing, as one of the requirements is that the job must be done by a certified company, so you're still saving money when doing it yourself without getting the subsidy.
Good work, totally worth getting the best to do that kind of work.
Hi i like the video however its a myth externally insulated buildings dont suffer with this problem.
Consider the scenario. Cold house, You return home on a cold day and put the heating on. You increase the temp & humidity in the home but the thermal mass of the wall is slow to respond and lags behind the room temp. The moisture enters the fabric due to higher humidity internally compared to outside and as the thermal mass mass of the wall is slow to respond Dewpoint occurs instantly on the inside of the wall. Moisture migrates through the fabric and becomes trapped behind the external insulation.. Bad bad bad bad. Only mitigation against this is a mechanical ventilation unit to combat the humidity rise.
Internally insulated walls respond quickly with the rapid temperature change and do not lag behind the internal temp. Most insulations used for this have low permeability and and moisture going beyond the insulation is minimal. Also with the external structure not wrapped in external insulation, the building will eventually permeate the moisture to atmosphere instead of being trapped. This is why timber frame buildings use an internal vcl eg polythene and external vapour control layer which allows moist to escape to atmosphere . The other way around would be a total distater.
Spent 13 yrs testing /investigating building defects, air leakage testing. Cavity filled and externally wrapped solid wall buildings are something that keeps cropping up...
Wow fantastic comment esp. with all that experience behind you. It does make sense what you say but I'd have thought that even with the heating off for the day the external insulation would keep the brick walls reasonably warm, certainly more than uninsulated walls but the point about moisture getting trapped outside of the wall but inside of the insulation makes total sense but again, will it condense?
I've been hearing about issues with cavity walls so let's say you were doing a brick/block extension, how would you build the external walls - internally insulated?
Any update on how this has worked? I thought it was best practice to take up the flooring and have the insulated board go all the way down to the top of the ceiling below, you have left a big gap under the floor board area so would be nice to know what its been like 1 year down the road... Cheers
ah man, this was a really good video, was just looking for the next one where you do the window cills etc and you never made one 😢
Amazing work and thanks so much for sharing your knowledge
One problem you can get doing this is before you put insulated boards on you can see if you have water or damp coming through the walls but once you have stuck insulated plasterboards on you will never know and in those cases you can get black mould form behind the insulated plasterboard.
If your pointing outside is all good you may be fine but if it’s a single 9 inch brick wall you may get penetrating damp, if the wall has a cavity you should be fine unless the cavity is bridged anywhere, remember black mould is a living organism and you only need a small patch and soon the whole back of the boards will be covered.
great video and well detailed , thanks
From my experience i would not use dob n dab on foil faced pir foam backed plasterboard as the adhesion between the foil face and the dob n dab mixture may seem sufficient initially i have found that it will separate after a short period of time.
That's exactly what I thought. Having a paper back is smart from GTEC.
A good trick to not create a visible butt joint if you can’t fit a full board in a space, instead of fully cutting in half you can score the back side and snap the plasterboard, leaving the front paper intact. Works well with normal plasterboard, maybe some sealant in the back where the cut was in this one could work
Very well explained. Thank you 👍
Did this to our Victorian bedroom a few months ago! I had a few added complications, namely having to replace all the double glazing and dealing with a bay window. Cutting that insulated plasterboard at a perfect angle is quite the challenge! Otherwise you did pretty much the same as me. Great work.
Sounds like it's holding up nicely. I have a half-hexagon bay window downstairs and was wondering how easy it is cut the angles. God to know it's doable, well done 👍
@@AliDymock I used a digital angle finder to work out roughly the angle to cut. It doesn't help the the original walls, ceiling and floor were all wonky so I needed to use a lot more foam at the bottom to get the boards plumb. Fill any big gaps with more foam to prevent thermal bridging and slap on some bonding to make up any significant gaps.
A nice video with great information. Subscribed.
Good video, our house is a 1934 property with solid brick walls. We had a external wall where the hallway/stair is. The plaster had blown and wall was sweating as you could feel it and almost smell it. We removed all plaster back to brick and allowed the wall to breathe and dry out. After a few month we got to work but only had a depth of 35mmish to use where no suitable insulated board product would suffice. After some research we applied a tanking slurry, a render mix and floated finishing plaster on top. Wall is dry as a bone now and no longer that cold to touch wall... but videos and knowledge is needed on the subject as there is so much conflicting info!
Tanking was smart!
Good video. How did you prevent moisture migrating and condensing around the wooden beams? I'm doing a similar job but I'm afraid that the wood in the walls will rot because of this excessive moisture.
Excellent Ali. Really informative
Pajama renovating...intriguing
If you had removed the plaster board on the front wall would that have saved you a significant thickness? Thank you for a superb and very clear description.
Hi,just wondering how your getting on with the insulated plasterboard,if you’ve had any issues and if it made a difference with keeping your house warm?
Good tip with emptying the rad. Just a note re cavity insulation from the 80 ( and 90 and even into the early 00s) only a lawyer of about 50 mm would likely have been added, still leaving a 50mm cavity which can still be filled to greatly improved the overall insulation. The cavity insulation would originally have been installed by the block/brick layers and could often have been poorly done as they would have been working around wall ties which caused gaps. The insulation would also have been low density polystyrene.
Great bit of info! That would be the best starting place for insulation if that is the case.
Your videos are so good! Full of such good information. Well done 👏👏
Thanks Simon, glad you like!
Did you check the vapour resistance of the boards you used? Depending on the thermal value of the construction it may not be enough to stop condensation, lots of these insulated boards claim water vapour control even though they have quite poor water vapour performance or no dedicated vapour control layer at all - general suppliers also tend to get this mixed up.
Can you recommend a board with suitable VCL ? I thought most were foil backed - is this not enough?
@@jve Knauf Thermal Laminate Vapour Check
@@Swwils thank you. I could only find these in polystyrene version, not PIR. I see other vendors have vapour barriers that are to build regs standards e.g. Recticel supply a PIR / plasterboard with vapour barrier (Eurothane PL) that conforms to EN ISO 10456. Have you come across these?
@@jve You just need to make sure that you are actually getting what you need, there are two main vapour resistance values used so it can be quite confusing. Your supplier might not know the difference - if in doubt contact the manufacturers technical team directly, they will be of massive help.
You'll see typical boards like XPS that has no vapour control layer with a resistance like 12.8 MNs/g or even the regular thermal laminate that has no resistance at all but then ones with vapour control layers will be around 80 to 150 MNs/g like PIR laminate.
Its amazingly sticky but expands and my experience is that it is a powerful expansion..and can create all sorts of bends.
That's interesting, i didn't get that kind of effect, it didn't really seem to expand much at all, nowhere near like expanding foam anyway.
@@AliDymock I fixed a door frame to a stone wall with expanding foam and saw later it had bent the vertical sides inwards. By way of a blokey aside we came across the "two part mix" for making expanding foam and so filled a hard plastic barrel, screwed down the top and 2 minutes later nearly got blasted off the earth by a fantastic explosion! Covered in it.. hair clothes the lot! Amazing!!
No it doesn't. There is minimal expansion on ADHESIVE foam. Do not confuse with Expanding foam.
@@deanoh6414 an important detail that should be emphasised. Some insulation is expanded polystyrene and I have a feeling that expanding adhesive-foam might disolve it.
@@andyharpist2938 Again nope. Because you don't apply to the polystyrene layer. Its sandwiched .
Great video well
Done 😊
Great video, i done this throughout the house all external walls last year using kingspan plasterboard sheets. I Would recommend soudal plasterboard adhesive, great stuff, then big twist headed helical fixings.
Great tip! And I love Soudal foam, defo worth the extra few £s over the No Nonsense stuff. I didn't know they did a plasterboard adhesive type foam though. Good shout on the fixings, my one regret on this.
Thanks for making this video, I've found it really useful. How many canisters of insta-stick did it require for a wall this size?
Warning, if there's a chance that the room temperature will drop below, I think, 5C just closing down the TRV is not enough as they open at about this temperature as a built in anti-frost setting. Use a proper screw on valve depressor thingy, they usually come with the TRV. Been there done that, didn't enjoy the soaked floor experience!
Secondly, I think the insulation on all these insulated boards acts as a vapour barrier.
I build a sun room 7 years ago 6m by 5m,,windows on 2 sides and 2 sky lights (velux window)
i have 300mmcavity walls , i got them pumped with insulation , and on the inside walls i put insulated plasterboard 12mm plasterboard with 35mm insulation, its very warm with one rad about 1.5 m long under a window and on on the wall about 300 mm wide and 1.5 m tall, the roof is a warm roof, worth every penny, and looks good too...
great video man
Sounds great! Is it cool in summer too?
@@AliDymock yes,lots of glass but , i put on extra long eaves, i picked it up while working in Austratia, it works there , so why noy try it here, im in the Rep of Ireland. the sunny southeast,,;-) the sky windows are on a remote and close if it rains , very handy
Being a solid wall from the 1920’s have you got lime mortar solid walls?
We’re looking to internally insulate our 1890’s cottage but been advised repeatedly by preservation companies not to use gypsum plasterboard or create a vapour barrier on the external solid walls. We’ve been told the solid walls need to breath. Going with a wood fibre board and a lime plaster finish to avoid any damp issues later.
Really interested to see how the insulated plasterboard works out for you. Cheers for the video.
I think you are generally ok with gypsum if you have a damp proof course thus helping the wall above it to stay dry. In old buildings with no dpc the walls can contain considerably more moisture and need to breathe, lime plaster allows this while gyp doesn't. Also consider the paint over the plaster as this will need to be permeable as well and lots of modern paints aren't. Full disclosure I'm not an expert.
I have been advised the same solid wall needs to breathe. I thought of why not use good roofing membrane on the solid brick wall which is breathable and acts as a water vapour barrier on the wall then batten up and use rockwool (insulated and breathable) Inbetween then use moisture plasterboard used for bathrooms?
Good job. Any thermal bridging since installation? They say don't stick stuff to external walls..!?
super helpful
Good video enjoyed it
While floor up, should have spayed the joists ends with anti-rot /wood worm. Because the insulation you used between the joists is less air tight than that above this becomes a cold bridge. Any moisture under the floor will condence on the outside wall. Spay would extend the joists life by 20 years ish.
You mentioned possible use of polystyrene. NO. In the event of a fire this will kill you quicker than what you have used. Also moving forward, if you ever needed to rent the place out, polystyrene is simply not allowed.
Do not take radiators off like this, you'll get lucky a few times but the valves can come off especially in older houses. Always hold the valve steady with a pair of grips whilst unscrewing the radiator.
Nice job, but get ready to have mould start growing where you've used uncovered metal fixings at 11:49. The warm air will condense on the cold screw head and you'll have a lovely grey patch to keep wiping clean during the winter.
Hmm I can’t imagine it would happen any more than on the windows but we’ll see. Have you got a link to fixings you would use?
Hi Ali, thanks for a great video. Can I ask, if you are getting a new EPC certificate for this house, do they check if it's done by a certified installer or do they accept DIY jobs and presume it's installed as per product manual? Thanks
No they don't check any certificates, just ask what has been done.
I've read that moisture can travel from outside inwards through the wall. Is this something you considered? I think there are special coatings that can be painted on to the exterior which will stop water getting in but allow moisture to escape. Thanks for the video :)
Just a note of caution. What ever you do to improve the thermal efficiency of your property. Please remember when getting an Energy Performance certificate for your property, improvements need to be evidenced either visually or with specific documentation. When it comes to DIY, this may prove difficult.
Tape and jointing not be too easy when butjoints and not tapered joins
However you can get fiba tape ultra thin which will help. A wallpaper would also.
The top range insulation lining paper and ready mix glue is a pretty good budget option its £100 a 1m wide roll. It does work to an extent. Used in own property.
Yeh I've done it before and just had to feather the butt joints a lot, it came out well. I used paper tape, didn't know about an ultra thin mesh - thanks!
I don't see how this is a continuous vapour barrier if the foil is on the back and the acoustic sealer is on the front, with a porous material and the thin air gap of the crack where panels abut between the two airtight elements. I may be missing something though. Thanks for sharing your experience as always.
Any condensation problems a few years later?
What’s the brand of the boards ?
What adhesive to use for sticking PIR to Plasterboard?
How did you add the radiator to the insulated plasterboard?
Top boy Ali
🤘Another vid dropping shortly!
@@AliDymock Just like buses ... three in a row !! :)
Such a useful vid, thanks Ali. Anyone see any issues with tiling over this type of system? with the extra fixings it should be plenty strong enough for a grout and tile finish in a bathroom right?
id be really concerned about creating damp between the cold brick wall and the insulation. You mention that we create a lot of damp in the internal atmosphere of the house with cooking and showering etc, i'd consider a MVHR (mechanical ventilation with heat recovery) system to try to keep the internal moisture levels to a minimum. I'd be interested to see what this was like in a year or so and to see if you do indeed end up with damp or rotting joists.
Check out Peter Ward on youtube, he is an expert on damp in old solid wall buildings. Scary stuff damp.
Yes
I agree with the choice of insulted plasterboard just not a fan of sticking it as a fixing, you can get fixings especially for insulated boards that give a much better fix
Have you got a link?
@@AliDymock don’t usually buy them on amazon but these are the closest to the ones I buy at our local building merchants, just drill a hole and hammer them in. The take a great fix
Electric extension cable clips are now available no need to move the socket just extend the cable.
Ah perfect. Thanks for chipping in with the knowledge!
I was advised by my council to fit tantalised timber on the wall first and 72.5 insulated plasterboard, what's your take on that?
Take a look at damp Sam he used insta stick and a safe guard acrylic little dot and dab
Great videos you are making, so after 2 years how is it going with the walls?
Could you stick on acoustic boards using the foam and would it work to deaden the sound more than drywall adhesive or fixings? Possibly 2 layers of acoustic plasterboard?
How do you find it now any issues?. I'm worried there wouldn't be enough ventilation behind to allow the brick to dry out ?
Great vid. Really helpful!.How thick is the line of foam when installing it to the wall?. 10mm?
Hi Ali.
I'm looking to do this in the next few months. Can I hide a gas pipe in the insulation,by cutting a channel out the back of a panel. Great video. 👍
is that stuff the same as drywall? sorry not familiar with this material.
Great video. Thanks! Will this solution work for a loft conversion where there’s one side wall which is party wall to next doors loft (unconverted)?
I would of built a stud wall, then use king span insulation then use thermal board. This way the board will be more secure and fixed correctly.
Just too much space lost unfortunately to do this. Not a big room 3 x 3.9m but your way is certainly better U-value and probably more solid too
Hello, the link to the plasterboard is expired. Can you confirm what plasterboard you used exactly? Maybe a new link or the full name please?
Hi check the plumb of your walls first and indeed how straight the existing wall runs because it may interfere with your boarding and it’s a real pain to have to undo your work because you realise there is an issue that stops you achieving a plumb flat wall
Great video, just what I was after, wheres part 2 cheers
Cheers! It’s the sound proofing one on the next wall, it’s on my channel. Bit of a faster pace than this vid 👍
Do you have a video of adding insulated board to a bay window? Mine has ancient expanded poly tiles over the insides of the solid stone window mullions. This looks terrible and the joints/gaps encourage mould. However Im not sure how to mitre the boards to fit?
I Want to do this in my daughter’s room. I have a couple of questions if hats ok.
1) Do you only need to do the outer walls? I was planning on doing all 4 internal walls in her room but if I don’t need to then i can save money!
2) I saw on another video about foam insulation where they advised to have a gap between the insulation and the wall to prevent condensation. (I’m going to have to take the plaster off as it’s in a mess) is it safe to stick it straight onto the brickwork without a gap?
Thank you
You can insulate internal walls for sound but it's not really needed. It's better to have an air gap and vapour barrier to external walls.
what if you just paint the brick with some like acrylic paint so there is a liquid barrier? Paint is thin. or even paint the brick with clear epoxy?
I'd like to do this in my bathroom and apply over existing plaster which has been painted. Would it be best to remove the existing paint before installing the thermal plasterboard?
9:14 Just a tip for the future. You could have left the corner on and cut it off after installation with an old saw, just cut in line with the opening. Or hold it and cut along the window before installing. Saves all the measuring and marking.
Good point. About to do another room the same way so will do that to make things quicker. 👍
@@AliDymock The reason I mentioned an "old saw" is that I've found that cutting plasterboard seems to have a very corossive affect on saw blades.
Not going to lie, when I first saw you doing DIY in pyjamas and flip flops, I thought what the hell!? However as the video progressed I realised it was you (outside building guy) lol good informative vid 👍🏼 P.S Any update on the heating bills situation?
Hello, Great video. Is it not necessary to bring it back to brick when doing this job? I’m going to undertake this in my sons room
Can I tile this board when fixed this way? Would it hold the weight of the tiles in a bathroom? Thanks