Here's some affiliate links to the floorboard lifter I'm using: UK: amzn.to/3xOBbe9 US (slightly different to mine): amzn.to/3g0ksPk See video description for more information about affiliate links
Howdy Andy from Dublin. . Just did the whole top floor of my circa 1906 victorian house. I use a Bahco BK36 nail puller to get out awkward nail stubs etc it's an absolute monster!!!!! Stay safe stay well bro ❤👍❤👍❤
When my dad removed a air vent from our early victorian house we found a newspaper had been blocking it for years. It was a complete newspaper from 1916!
I'm currently doing a similar thing myself and I wanted to reduce the amount of dust and loose debris from the insulation as much as possible. I did some research and ended up buying some soft material jigsaw blades to use in the jigsaw to cut the PIR. They work like an absolute dream, clean straight cuts and no dust or debris at all. I mean none! I was amazed by it, I would highly recommend them if cutting rigid insulation.
Great work as always , I know from personal experience that the thicker insulation would be harder to push into place under the floor boards . The slittiest difference in the gap between the joists and it locks sold, so what you have done is definitely the way to go . I love your approach to everything you do even down to cleaning out all the rubbish that has no doubt been there since the house was built . You’ll have to put a peace of wood under the floor with your name and date when this work took place , so in another 100 years someone will say this chap made a wonderful job of this house bless him . Best wishes and kind regards as always 😀👍👍👍
I had this exact same job to do myself for a 1925 house and I used scaffolding mesh to create a hammock between the joists. Then I laid rock wool on top. It was something like £1 a roll at the time so it saved a lot and the limited joist depth wasn’t an issue. I think I put a vapour control layer on top of that and then nailed the boards down. My main concern throughout was to avoid moisture buildup in the timber as this leads to woodworm which we had an existing problem with. The rock wool doesn’t trap moisture (which is another reason for choosing that) and also all the air bricks needed clearing out to get air flowing under the floor. 12 years later and the woodworm issue has been sorted ever since. I like your method because it doesn’t need all the floorboards taking up which a massive time saving. On the flip side, the good thing about taking up the floorboards is that when you nail them back down, the gap in between can be closed (to stop draughts) and this saves a job later.
I have nearly got all of our small bungalow done now the only difference is that I put ply on my battons and I moved my heating pipes into troughs in top of PIR. Heating pipes under ventilated floors has been a gripe of mine for 20 years when Energy Saving Trust were banging on about poorly insulated hot water cylinders. Yes I cleared it all out, hoovered it, as I went, a lot of builders see floor voids as skips, I also mortared in the joists, something the builder didn't do and sealed up everything. I did seal up some vents that faced the joists and so I couldn't duct them down into void. The vents on the open ends of the joist I ducted down and we have a lot. To rigidise the floor I did put a two brick pier under joist, we are on a concrete raft so easier than most, I used engineering bricks + slate + DPC. We have an EPC A, I am not sure its good enough for an A, though I think they have A+, A++ to create higher levels. We see a lot of properties around us being bought and 'done up' they always keep the original feature of an appalling EPC, which is crazy. If a property is done up then it should be compulsory to improve the insulation because once you have fancy bathrooms and kitchens no one is ever going to tear it apart.
Where were you and RUclips 20 years ago. I learnt so much renovation my own house and after watching this video I now know how a professional does it. I would have done it the same way if a didn’t have concrete floors.
It's lovely to note a kindred spirit who clears up the dumped waste from previous and indolent tradesmen....I'm handy with a vacuum cleaner and brush and pan too !
OK, please allow me help you. I have MSc, specialising in thermodynamics, and did my thesis many years ago on suspended timber floor insulation effectiveness. I am now an thermal consultant for aerospace applications. You need to spring force the insulation upwards to be in constant contact with the floor. Eg; use something like a PLY curved/sprung slat from a bed, screwed to the underside of the joist so that it bends the slat straight and always forces the board against the underside of the floor. The are numerous leaf spring alternatives. The air bricks & positioning are designed to cause a purpose draught between the joists, directly at the end face of the insulation that is later installed. This draught is now forced to go around the insulation with a venturi effect pull at the opposite end. The slightest gap between the PIR & the floor board causes a small channel that the air blows/pulls through at high velocity, sometimes whistling or chattering the PIR & floor boards, thus the insulation does little but act as a conduit. You will also have small gaps in your floor boards tong & groove, that permit 'cross-flow' across joist. The problem i'm describing doesn't usually happen in lofts due to the gravity on the insulation that moulds to the face it's laying on. There is visible clearance in your video (top & sides of PIR) and you wouldn't have been able to slide the PIR in to the slot so easily under the floor boards that you kept in place if there wasn't a clearance. You could partially rectify this by getting the floor boards up at each PIR joint and spray insulation foam (2mm thick, 100mm wide), before putting the floor board back down. This will 'closed cell' seal the openings of the gap that you have created. I have written this with my best and positive intentions, so neither you or your viewers make the same mistake that 99% of installers are making. Suspended underfloor insulation is one of the most disruptive and longest payback. If you go through all the trouble, you need to to it properly else it will NEVER payback. If a jobs worth doing well or don't bother. A few technical improvement would transform the performance from 20% to 90% effectiveness, potentially saving £90 per year instead of £20 per year in heating costs. I wish you well, and if you want to make a proper video on all the critical things to get right, I'd be happy to help you.
Just a quick question you say you have a degree I thermodynamics and ypu are an insulation consultant. Then why did building control pick up on the fact that your insulation wasn't touching the underneath of the floor board and was creating a duct resulting in heat loss.
I think you need to get yourself up to speed on Gapotape - I seen it on another youtube install by skillbuilder and as they say in the vid it is a COMPLETE GAMECHANGER - I will have to get them to speak with you Mac ruclips.net/video/Omk68Z-tE7U/видео.html
@@nathancurtis2585 My MSc thesis was 35 years ago and was substantially modelling the theory. It did not consider the modern materials used today, the full practicality of achieving the optimum theory and modern day best practices. Since then, my work has been biased towards aerospace applications. Due to my background, I was able to talk to BC on a very detailed technical level. They didn't pick-up on your 'alleged fact' that my insulation wasn't touching, because I haven't even started my installation yet. During the convo, they told me to make sure that when I do my installation, I ensure no gaps for the previously explained reasons. If you think about it, a 6kph breeze equates to 1.7 m/s, meaning that the warm air is washed out the gap and replaced with new air before the heat reaches the insulation. Armed with this knowledge, I looked at a few youtube videos for more practical tips, and saw that this critical basic principle was not being taken seriously. One other thing they mentioned was to apply sticky back foil tape to the top of the joist, overlapping the PIR (not possible from underneath). This delivers continuity of reflective surface and seals the possible air leaks with one continuous reflective & leak free layer. The effectiveness of the installation can be severely limited if you still have draughts. Hope that helps and all makes sense.
@@markfetherstone2885 Thanks Mark. I hope Nathan watches that video. It looks a great product and the video explanation on the 'performance gap' really does agree & emphasise my point on sealing all the gaps. Retro fitting suspended floor insulation can be very disruptive, and you must get it right else you'll have wasted your time & money. Shame they didn't explain a solution to keep the PIR board tight against the underside of the floor boards though, unless they coat the top of the PIR with the foam tape and compress it (super expensive). As presented, the PIR will work it's way down and create a conduit. A sprung batten would do the trick.
Good progress - until your comments about a wood floor going down my thinking would have been to just rip up all the floorboards, batten and insulation and then fit t&g flooring chipboard (screwed down) - the time saving probably out-weighs the cost of the chipboard (and lots of floorboards to re-use for something else). AND the pallet breaker gadget is great - I have a home-made version that cost me almost nothing!
@@Game0verFool nothing wrong with it. Im about to rip up my old floorboards in the lounge insulate put chipboard down and glue oak on top. My guess is Andy is confident the boards are flat enough to glue to or hes going to overlay 4 or 6 mm ply which will eliminate any potential drafts that still may exist and saves a few hundred quid on chipboard.
I was reasonably careful when taking up the floorboards on our '30's property, they were not tongue and groove, and I'm happy to accept some character in my sanded floors, but the pine came up beautiful after a couple of days of sanding per room, much nicer than many of the fake wood floors available to me. And with the variable diameters of gap filling high density foam, for wooden flooring available there are not concerns with knocking over a glass of water, which would be an issue without the foam.
me too but my 1930s board were t&g. I spent ages lifting carefully while preserving the t&g and managed to remove about 1000 carpet tacks, insulate with sheep and reinstate , sand and osmo. look absolutely lovely. Importantly the whole of the ground floor has the same floorboards and so its all on the same level.
@@twmd got the downstairs to do like that still, luckily in my case without T&G, but should still be fun, need to put in new 32mm water line first thought.
@@cjhification good luck! I found all the bricks from a old fireplace underneath nad a pack of woodbines from 1930! worth planning some time for cleanout.! I added a new radiator and needed to extend the radiator feed pipe in both directions so worth considering all possible jobs that are easier with the boards up!
I hope the void under your floors are well ventilated otherwise look out, we have just had to replace the entire floor joists insulation and deck as the builders did not install adequate ventilation and 200 x 50 joists had decayed and only 75mm was left in places after 12 years!
Haha reminds me of when I pulled up my floor recently to do this job and found that the original 1920's joists were daughtered up to replacements from about 1980. Both turned to dust when we pulled on them. The air brick had been blocked up for at least 70 years by the looks of it. ;0 They went to the trouble of replacing the joists but never bothered to check ventilation or figure out why the originals had dry rotted. We bricked up the fireplace and put an air brick in below the insulation level and replaced all the joists with reclaimed timber. Treated the ends etc. Solid as now. Last another 100 years no question.
Exactly what I came to RUclips for i just bought a house with a suspended floor possibly 1950s an really wanted to insulate the floor now I’ve watched your video I have not only learned a lot (discovered a new tool pallet buster ) I’m even more confident of doing it thanks very much for taking your time to do this video it’s much appreciated
Been there done that. In 2017 I removed all the boards at one time, cleaned out and vacuumed underneath but then put a breathable membrane "up and over the joists" sealing in at edges then laid in sheeps wool insulation and put a new floor down. Stank like a barn for 6 months (not thereafter) but the insulation and sound proofing that it provided is on another level.
I'm planning to do the same in a few months so it's good to hear it makes a difference since I was a little worried that it wouldn't be worth the hassle.
@@elobiretv VERY much worth it if you do it properly. NO draughts, silent, breathable and the house warms up so quickly it's un-real. Huge reduction in heating bills. It's more work than using Celotex. As I have wood flooring, If I had my time again I would have considered running tubing underfloor as central heating and warming the whole floor area rather than radiators but that is another discussion. Hope this helps.
When removing nails from joists, I always give them a whack with a hammer first - it drives them slightly further in, but it also breaks the bond between the nail and the wood which has formed over decades, which makes pulling them out a lot easier.
Excellent video. Nice to see a builder cleaning out under the floor, it's usually used as a disposal area. Most important to seal all gaps so drafts can't get through particularly round the walls which some people forget about and the wind whistles in under the skirting boards.
Thank you for the good guidance. Best not to cut the Ecotherm outside on the grass though. It won't break down in the environment. Better to cut it somewhere you can sweep it up or collect it afterwards. Technically polyisocyanurate is recyclable, (but left over sawings won't be), but otherwise it might go to an energy from waste plant, (or landfill).
I’d personally use a multi tool on the first floorboard so the cut doesn’t overlap and then circular saw the tongue & groove parts sections. The boards lift pretty well that way and virtually no damage. I’d also try to stagger the cuts so the cuts are all in a line, if that makes sense. Thanks for the video though 👍🏻
How architects differ. Mine advised not to use PIR but to sling a breathable membrane on the underside of the joists then fill with 200mm of minimal wool. Fortunately, there was sufficient crawl space to get underneath and staple the membrane securely. Apparently this method is used frequently when restoring listed buildings.
I think there's a number of methods depending on building age, crawl space size etc. There's some best practice stuff here: www.gov.uk/government/publications/insulating-suspended-timber-floors-best-practice
@@GosforthHandyman 🤣🤣🤣Crikey, I bet....3 days to do two rooms! I am sure it will be worth it. My house has solid floors and when I came to live here it had old ...but clean wool shoddy underlay. Brilliant stuff.
I did this when I moved into my bungalow late 2014, and put DPM on the subfloor to prevent moisture from the ground before keying in the insulation , cleaned up all the crap from the previous tradesmans work aswell,renewed the old floor boards for 22mm Caber floor....job done 👍
The exterior walls and floor joists are thermal bridges, even if you insulate the outside of the walls they are in contact with moving air bellow the floor allowing heat to transfer from inside the room down the wall, also through the flooroards through the joists, so the room is still losing heat
I've been watching for about two years now and I have to say that the quality of the videos has improved. You've gone from really good content to magnificent content. I don't usually notice music in videos but I did here. I like it. If you've recently changed to the format, please do more. If this is consistent with prior vlogs, please accept my apologies for not noticing, and keep up the good work (phrase stolen from Essential Craftsman)!
Thanks - really appreciated! It's proportional to how much time I have for the edit. So now we're a bit further on with the reno I can take a bit longer making the edit nice. Next: More and better B-roll as I never get time for this. 👍😁
there should be a layer of breather membrane installed prior to installing the PIR, then the joists taped to act as a VCL. Without these any moisture going in between the PIR and the joists will ruin the joists.
Tip for those impossible nails: The large curved back of full sized, vise grip pliers make an excellent fulcrum for pulling fasteners. You can *pull* out screws if you want to. Nails are usually easy. Even if you just have a few mm exposed from a broken nail you can still lock on and roll the pliers against the wood to pull almost anything. For the really hard ones, or brittle materials, you'll pull a few mm, then release and grab at wood level again, so you don't break the fastener off and make things worse.
You do such a careful, neat job on things that don't show, so only your RUclips followers will know! Well, perhaps a workman 100 years from now may have reason to take up the floor and will appreciate the workmanship.
Thanks so much for this. Was lining up the job myself but it's clear that 1) it's too big a job and 2) as i want to retain the existing floorboards, i'm better off just leaving it as it is for now.
Just insulated a 100 year old kitchen extension on a house. I found a RUclips video on cutting insulation where a large scraper has one side and the front edge ground to razor sharp with a grinder. Mark board, use 2 or 3 inch straight edge to run the scraper at a perfect 90 degree. Once scored in by around an inch, throw straight edge to one side and run blade through by drawing it towards you with increasingpressure. The best part being thar using a wide blade, the cut remains straight right through once started as board holds blade straight and NO MESS. It worked a treat and with practice, really quick with perfect straight and smooth edges ideal for squeezing in. The sharpened front edge can be used as a trim knife to assist inaccuracies in floor boards and joists as will as cutting out obstructions. The bigger the scraper the better, ONLY grind one side and mark it as I did both and managed to slice a finger when pressing it down without thinking. This leaves one side safe to touch and push in for deeper cuts..
@@BoxerfanUK you mean for cutting? ruclips.net/video/1cv46GuniIY/видео.html Not sure this is same video but same idea. I sharpened a wider scraper than shown but either should work. Just get it razor sharp but watch your fingers, especially slicing in.
@@GosforthHandyman I just did what you have done last but year, bought mine ripped it back to brick and its done now so that won’t be happening now lol. I tore mine apart then lockdown happened and I was living there in one room and I had to buy 35 bags of plaster from gumtree for £20 a bag because there wasn’t any anywhere
Just been chatting to building control. They tell me that I need to make sure that the insulation is compressed against the underside of the floor, otherwise the warm air will simply wash away though the the smallest gap between the floor & insulation, making the insulation have no effect. Your boards were not touching, so what did you do about stopping this convection path? They said that this doesn't matter in a loft because the insulation always falls/compresses tight to the ceiling, but the opposite occurs under floor.
The batterns where installed so that the top of the insulation was flush with the underside of the floor boards. Your never goinf to get it compressed. Even after installation you will never get full compression with constant walking g and furniture as this will slightly displace it anyway.
@@nathancurtis2585 Good point and explained in my other post. That's where they suggested a sprung batten to always push the PIR up against the underside of the floor. The walking on the floor will not displace the PIR at the joist. The PIR will flex with the floor between joists and spring back up with the board. Imagine a curved PLY bed slat screwed under across 2 joists with the centre permanently pushing the PIR up. An alternative is to seal the gap at the ends of each board. The springiness of this particular video installation will be compromised by the lack of tong & groove / damage that would normally act to improve support via neighbouring floor boards, but singularly the will flex more. Hope this helps.
My question is what about draft? There as a many holes in between the pir as there are between floor boards. The warm air is going to seep out of there fast. I have put a damp proof membrane between pir and floorboards to stop any convection.
Great video, one extra tip is to fire the brad nails in at opposing angles, makes the pull-out retention much better especially with brads. 👍🏻 Also, expanding foam (using a gun for control) works great to stick the ends of PIR together, and along the batons if dropping the PIR from the top to seal.
Love it - and sounded like you enjoyed doing the job too! Shout out to your new massive dust pan & brush - two videos in a row. Spied them in Screwfix...impulse purchase incoming!
Just a thought and to add a degree of crazy... Under cut both dimensions by a half inch. Float it on your nailer sticks. FOAM a quarter inch gap all around. Then, there is no air gap in those imperfect hand saw cuts. Not that you had many. I know i do! Cheers.
I'm ambivalent about drafts. I know they are not good when it comes to energy efficiency and cost but they have saved our lives in the past. We once rented a place that had 2 appliances sending out carbon monoxide, unkown to us, one gas water heater in the bathroom and the living room gas fire. There was no central heating. Probably the only reason we survived was the draftiness of the flat. Where we live now is also somewhat drafty but when one family member in the house had Covid, no one else caught it.
Only breathable insulation should be used in the old sub floor. The timbers will sweat and over time will rot. Same problem as using spray foam insulation in the loft. It prevents air getting to the timber to keep them dry
Hi Andy, Great video, i have been following you for a while and you have helped with my renovation works. I do have a question, how close to the internal/external walls should the insulation be? how can i stop draughts coming up at the ends? A Response would be gratefully appreciated.
1 year on, was it worth the time/expense ? I only ask as we moved into a bungalow where the only room which is a problem is the master bedroom with three outside walls with a big bay window. Next job is to install insulated plasterboard and possibly the floor .
This is a really good video bud : ) ... one thing though, it is important to also check drains prior to installing insulation as the moisture balance can get tipped in a floor by adding insulation, and it isn't unusual for timber decay or woodworm to pop up in the future.
A great video, Andy. You are so knowledgeable and I appreciate you sharing. My son put a nail 40mm into his right foot yesterday. He tells me he’s finding stairs a challenge so no ‘Ray of sunshine’ smiley face today.
I've recently insulated all our floors with rockwool + Floorquilt By YBS main reason was fitting underfloor heating and it needed doing anyone doing this the floorquilt is well worth it as a secondary layer
I like your method for fitting that insulation. I have a cat S60 thermal imaging mobile phone. I can see on my floor there are cold spots against the outside wall where the air bricks are positioned outside.
At least your floor joists are solidly in the wall or on hangers. When i did mine, they were just sitting on bricks and slate packers. Like yourself i used 75mm Cellotex, but i had to take up 95% of the floorboards (very narrow and solid red wood of some sort) . As i replaced the flooring with grade 5 flooring tongue and grooved sheeting. Also made sure all the old rubbish left behind by previous craftsmen (why don't they keep things tidy?) and plenty of air circulating beneath the insulation. I then used foil tape over the joists and insulation to remove any chance of draughts, with expanding foam around the outer walls. Even though i tried keeping the joists evenly apart, they were old and bent so cutting the insulation was very time consuming. Major DIY job for me but it is level and so much warmer. Really like your videos, enough detail without going over the top.
Absolute gold 🙏 Loving the methodical approach to this job. Lots of useful little tips to make sure you don’t miss the obvious. 😅 Cutting the end of the PIR boards at 45 degrees to help encourage good air flow-magic 🎉 I now feel confident enough to take this job on myself-thanks mate 👍
Nice long piece of 4x2 about 7ft will do for levering up those floor boards. Also, i’d say 70-80mm plenty thick as PIR. Only question is why wouldn’t you pin those battens to the underside of the joists? Looks like you have enough room to get a first fix nail gun in there at an angle which would be better anyway as skew nailing would better hold them long term. Just a thought anyway.
Do you sealant or tape the joints between each piece? Maybe it's worth putting a squirt of sealant on each edge so that there's a good seal when you push them together. On new builds, extensions, I've seen tape used on the joints.
I'm just about to get started with this job. What size of brad nails did you use to fix the battens? I am guessing something like 40-50mm (don't know much about nail gauges). I'll be tackling it all from underneath as there is enough space down there to leave the floor intact.
In the 1920s, houses were built with adequate air flow underneath the flooring to prevent mould and rot in the timbers as well as helping to create a draught to draw the coal fires. There is a modern principle in thermal insulation where you need to meet the thermal triangle of thermal, air flow and moisture. Using hydrophobic insulation prevents the flow of air and contributes to moisture, which encourages the growth of mould and rot. Instead, install a vapour barrier to prevent any moisture from the soil, then add a breathable airtight membrane to prevent wind-washing and let any moisture escape from the joists. Next use a high density hygroscopic insulation, such as sheep's wool, jute or wood fibre. Finally, add a vapour control layer before re-laying floorboards.
Wow.....do you have a RUclips channel? I have a Victorian terrace house and 6ft height in the cellar, can only access in by a small trapdoor in my back room. I need to insulate under there sometime this year, as the heating Bill's are on the rise. I need to cut down the cost! I would love to able to see some ideas on how I can do this job myself.
I'm thinking, if this was done to a floor upstairs- it would also improve insulation to the room downstairs too. Does that sound right to anyone, because we need to resecure some floorboards in the bedroom (and the living room is freezing) so while the floors up anyway.... Wht do you think?
The insulation acts as a vapour barrier here, taping over the joists and between insulation would make it continuous. Is it worth it when you'd still have bigger/harder-to-seal gaps around the edges? In his case he said he'd add a hardwood layer over the top too.
It's not recommended but it's optional for additional air-tightness. Not really needed in this scenario as would be a nightmare to fit. Useful info here: www.gov.uk/government/publications/insulating-suspended-timber-floors-best-practice
I have a comment. I feel for your knees and back! I've been working on my similar looking home, in the attic, where I can't stand. Just killer on the body! Great job and thanks for sharing!
Surely you should have sealed the celotex boards together and against the joists? All those gaps will allow cold air through and around the celotex, greatly reducing the insulating efficiency!
I've lifted a few floors in my time and it never ceased to amaze me how many revealed piles of pipe/cable offcuts mortar and other debris.Just plain lazy and untidy.We think alike Andy!
Have you ever considered using foamed glass to fill voids instead of PIR boards? I am always concerned about moisture condensing especially between joists and insulation boards. Wondering what is humidity level before and after installing insulation. I know you did good job on air bricks but still remember how many old building were damaged just by cement based plaster or pointing on bricks.
So want to do this to my house built in 2000. The bedroom over the garage has no insulation under the floor but my floor is t&g chipboard. I already sealed the edges which made a big difference.
instead of timber battens cut into small pieces could you use a flexible plastic angle trim that could be fixed in long lengths, under the floor boards..??
This brilliant.. Instead of the baton, I would use Expamet Steel Angle bead. If your joist is 100cm you then should be able to fit it in-between if using the steel angle bead.
That"s the proper way, all joins and gaps, regardless how small, should be finished air tight, just a 1mm gap between two pieces in several spots can affect the effectiveness of the insulation by 25%. And should a damp proof membrane between the insulation and boards or between boards and new flooring be used?
The 1mm gap / 25% thing is a myth - think about wearing a winter coat and having a 1mm gap - are you 25% colder? I would foam edges of big gaps if needed. Tape isn't part of the best practice guide but I guess is probably wouldn't do any harm: www.gov.uk/government/publications/insulating-suspended-timber-floors-best-practice
@@GosforthHandyman A winter coat? Pfft, I expect someone from the North of England not to know the answer to that question. If you'd said "a hole in your t-shirt", that'd be a better anology. As it happens though, I have a hoodie I sometimes wear when it's -2C or whatever, and it has these ventilation holes (maybe 2mm diameter) in the back. The draught that comes through them is intense, and I've actually tried covering them up for a bit of an experiment (with tape, but not in public, I'm not a total weirdo) and it significantly improved the heat retention! I was surprised. I don't believe the 25% thing. I do like the look of the gapotape product however, it looks the part, but I'm guessing it's horrendously expensive.
I really want to do this but having read that the foil membrane can be a cold surface for condensation, I am concerned I will introduce water issues. Don't you have any concerns over that? Even if I is well ventilated, so long as their is moisture in the air and the foil a cold surface, you could be looking at months of wetness every year that will eventually cause damage
The dew point is in the middle of the PIR. The top foil will be at room temperature. The bottom foil will be at outside temperature. Unlikely you’ll get condensation on the foil itself.
I wish I'd seen this a few years ago! I learned some of your lessons for myself in a Jesmond terrace, but that's a *much* nicer job than I've done so far. At least the hallways and kitchen will better, thanks to this video :-)
Could I use similar method to Sound Proof the floor a little on 1st floor? Just ripped off the carpets to fit wooden flooring. While I am here I'd like to sound proof it a bit since it'll be a kids room :) Amazing video. Thanks for sharing!
To be honest with you,you’re the first guy I’ve seen doing insulation in this manner. Normally it’s to expensive to have a man doing all this work for days on end . What happens in the real world you take a chainsaw around the outside edge and cut the lot. Fill it with insulation and put in a new solid floor.
Was there a particular reason why you didn't use spray foam to bond the insulation boards to each other and to the joists? That way the floor would've been air tight.
Here's some affiliate links to the floorboard lifter I'm using:
UK: amzn.to/3xOBbe9
US (slightly different to mine): amzn.to/3g0ksPk
See video description for more information about affiliate links
Howdy Andy from Dublin. .
Just did the whole top floor of my circa 1906 victorian house.
I use a Bahco BK36 nail puller to get out awkward nail stubs etc it's an absolute monster!!!!!
Stay safe stay well bro ❤👍❤👍❤
P.S.
Love the background music just needs to be a tiny bit lower for us headphone users 👍👍
I used thes for my old decking and it has i slot to remove nails and screws
A BACK SAVER
I recommend marking pipes and cables on top of the rigid insulation,, saves a load of grief at any later date if needed
Really like that I'm not the only one who loves to clear out under the floorboards if they are up.
Cheers Craig! Absolutely - hate leaving it like that. 😁
On the ground floor it also improves the air flow, any rubbish tends to suck up the damp too and it takes longer to dry out.
you can also find some treasure. Once I found pack of smokes about 80 years old. My friend smoked them and he is still alive, so I guess it was a win
Every other tradesmen uses that as a handy bin! Never known anyone to clear up under there. Part of the joy is reading the old newspapers!
my builder lost his wedding ring under my boards, its somewhere down there for future generations...
When my dad removed a air vent from our early victorian house we found a newspaper had been blocking it for years. It was a complete newspaper from 1916!
Oh wow - that's an amazing find! Never found anything that old. 👍
Found one today 1891 chinese religious newspaper under this jobs floor
handy tip, number the floor boards to go back in the same position to save cutting and adjusting in unusually dimensioned rooms later
I'm currently doing a similar thing myself and I wanted to reduce the amount of dust and loose debris from the insulation as much as possible. I did some research and ended up buying some soft material jigsaw blades to use in the jigsaw to cut the PIR. They work like an absolute dream, clean straight cuts and no dust or debris at all. I mean none! I was amazed by it, I would highly recommend them if cutting rigid insulation.
Great work as always , I know from personal experience that the thicker insulation would be harder to push into place under the floor boards . The slittiest difference in the gap between the joists and it locks sold, so what you have done is definitely the way to go . I love your approach to everything you do even down to cleaning out all the rubbish that has no doubt been there since the house was built . You’ll have to put a peace of wood under the floor with your name and date when this work took place , so in another 100 years someone will say this chap made a wonderful job of this house bless him . Best wishes and kind regards as always 😀👍👍👍
Cheers bud! There's a few messages hidden around the place. 😁👍
I had this exact same job to do myself for a 1925 house and I used scaffolding mesh to create a hammock between the joists. Then I laid rock wool on top. It was something like £1 a roll at the time so it saved a lot and the limited joist depth wasn’t an issue. I think I put a vapour control layer on top of that and then nailed the boards down. My main concern throughout was to avoid moisture buildup in the timber as this leads to woodworm which we had an existing problem with. The rock wool doesn’t trap moisture (which is another reason for choosing that) and also all the air bricks needed clearing out to get air flowing under the floor. 12 years later and the woodworm issue has been sorted ever since. I like your method because it doesn’t need all the floorboards taking up which a massive time saving. On the flip side, the good thing about taking up the floorboards is that when you nail them back down, the gap in between can be closed (to stop draughts) and this saves a job later.
I have nearly got all of our small bungalow done now the only difference is that I put ply on my battons and I moved my heating pipes into troughs in top of PIR. Heating pipes under ventilated floors has been a gripe of mine for 20 years when Energy Saving Trust were banging on about poorly insulated hot water cylinders. Yes I cleared it all out, hoovered it, as I went, a lot of builders see floor voids as skips, I also mortared in the joists, something the builder didn't do and sealed up everything. I did seal up some vents that faced the joists and so I couldn't duct them down into void. The vents on the open ends of the joist I ducted down and we have a lot. To rigidise the floor I did put a two brick pier under joist, we are on a concrete raft so easier than most, I used engineering bricks + slate + DPC. We have an EPC A, I am not sure its good enough for an A, though I think they have A+, A++ to create higher levels. We see a lot of properties around us being bought and 'done up' they always keep the original feature of an appalling EPC, which is crazy. If a property is done up then it should be compulsory to improve the insulation because once you have fancy bathrooms and kitchens no one is ever going to tear it apart.
Where were you and RUclips 20 years ago. I learnt so much renovation my own house and after watching this video I now know how a professional does it. I would have done it the same way if a didn’t have concrete floors.
It's lovely to note a kindred spirit who clears up the dumped waste from previous and indolent tradesmen....I'm handy with a vacuum cleaner and brush and pan too !
Absolutely! Can't leave it like that. 😁
OK, please allow me help you. I have MSc, specialising in thermodynamics, and did my thesis many years ago on suspended timber floor insulation effectiveness. I am now an thermal consultant for aerospace applications. You need to spring force the insulation upwards to be in constant contact with the floor. Eg; use something like a PLY curved/sprung slat from a bed, screwed to the underside of the joist so that it bends the slat straight and always forces the board against the underside of the floor. The are numerous leaf spring alternatives.
The air bricks & positioning are designed to cause a purpose draught between the joists, directly at the end face of the insulation that is later installed. This draught is now forced to go around the insulation with a venturi effect pull at the opposite end. The slightest gap between the PIR & the floor board causes a small channel that the air blows/pulls through at high velocity, sometimes whistling or chattering the PIR & floor boards, thus the insulation does little but act as a conduit. You will also have small gaps in your floor boards tong & groove, that permit 'cross-flow' across joist. The problem i'm describing doesn't usually happen in lofts due to the gravity on the insulation that moulds to the face it's laying on.
There is visible clearance in your video (top & sides of PIR) and you wouldn't have been able to slide the PIR in to the slot so easily under the floor boards that you kept in place if there wasn't a clearance. You could partially rectify this by getting the floor boards up at each PIR joint and spray insulation foam (2mm thick, 100mm wide), before putting the floor board back down. This will 'closed cell' seal the openings of the gap that you have created.
I have written this with my best and positive intentions, so neither you or your viewers make the same mistake that 99% of installers are making. Suspended underfloor insulation is one of the most disruptive and longest payback. If you go through all the trouble, you need to to it properly else it will NEVER payback. If a jobs worth doing well or don't bother.
A few technical improvement would transform the performance from 20% to 90% effectiveness, potentially saving £90 per year instead of £20 per year in heating costs. I wish you well, and if you want to make a proper video on all the critical things to get right, I'd be happy to help you.
Just a quick question you say you have a degree I thermodynamics and ypu are an insulation consultant. Then why did building control pick up on the fact that your insulation wasn't touching the underneath of the floor board and was creating a duct resulting in heat loss.
I think you need to get yourself up to speed on Gapotape - I seen it on another youtube install by skillbuilder and as they say in the vid it is a COMPLETE GAMECHANGER - I will have to get them to speak with you Mac ruclips.net/video/Omk68Z-tE7U/видео.html
@@nathancurtis2585 My MSc thesis was 35 years ago and was substantially modelling the theory. It did not consider the modern materials used today, the full practicality of achieving the optimum theory and modern day best practices. Since then, my work has been biased towards aerospace applications.
Due to my background, I was able to talk to BC on a very detailed technical level. They didn't pick-up on your 'alleged fact' that my insulation wasn't touching, because I haven't even started my installation yet. During the convo, they told me to make sure that when I do my installation, I ensure no gaps for the previously explained reasons.
If you think about it, a 6kph breeze equates to 1.7 m/s, meaning that the warm air is washed out the gap and replaced with new air before the heat reaches the insulation. Armed with this knowledge, I looked at a few youtube videos for more practical tips, and saw that this critical basic principle was not being taken seriously.
One other thing they mentioned was to apply sticky back foil tape to the top of the joist, overlapping the PIR (not possible from underneath). This delivers continuity of reflective surface and seals the possible air leaks with one continuous reflective & leak free layer. The effectiveness of the installation can be severely limited if you still have draughts.
Hope that helps and all makes sense.
@@markfetherstone2885 Thanks Mark. I hope Nathan watches that video.
It looks a great product and the video explanation on the 'performance gap' really does agree & emphasise my point on sealing all the gaps. Retro fitting suspended floor insulation can be very disruptive, and you must get it right else you'll have wasted your time & money.
Shame they didn't explain a solution to keep the PIR board tight against the underside of the floor boards though, unless they coat the top of the PIR with the foam tape and compress it (super expensive).
As presented, the PIR will work it's way down and create a conduit. A sprung batten would do the trick.
Old newspaper from Saturday April 21 1951, my mothers 16th birthday ! Enjoy watching your videos;
Good progress - until your comments about a wood floor going down my thinking would have been to just rip up all the floorboards, batten and insulation and then fit t&g flooring chipboard (screwed down) - the time saving probably out-weighs the cost of the chipboard (and lots of floorboards to re-use for something else). AND the pallet breaker gadget is great - I have a home-made version that cost me almost nothing!
Yup, would tend to agree. That would have made the job much easier if we weren't doing new wood floors. 👍
What would be wrong with putting wood flooring on chipboard?
@@Game0verFool nothing wrong with it. Im about to rip up my old floorboards in the lounge insulate put chipboard down and glue oak on top.
My guess is Andy is confident the boards are flat enough to glue to or hes going to overlay 4 or 6 mm ply which will eliminate any potential drafts that still may exist and saves a few hundred quid on chipboard.
Apart from the fact you are extremely talented, you also have an amazing sense of humour.
I was reasonably careful when taking up the floorboards on our '30's property, they were not tongue and groove, and I'm happy to accept some character in my sanded floors, but the pine came up beautiful after a couple of days of sanding per room, much nicer than many of the fake wood floors available to me. And with the variable diameters of gap filling high density foam, for wooden flooring available there are not concerns with knocking over a glass of water, which would be an issue without the foam.
Cool! Not T&G? Don't see that very often! 👍
@@GosforthHandyman there a bit wider than your boards I think, at about 170mm.
me too but my 1930s board were t&g. I spent ages lifting carefully while preserving the t&g and managed to remove about 1000 carpet tacks, insulate with sheep and reinstate , sand and osmo. look absolutely lovely. Importantly the whole of the ground floor has the same floorboards and so its all on the same level.
@@twmd got the downstairs to do like that still, luckily in my case without T&G, but should still be fun, need to put in new 32mm water line first thought.
@@cjhification good luck! I found all the bricks from a old fireplace underneath nad a pack of woodbines from 1930! worth planning some time for cleanout.! I added a new radiator and needed to extend the radiator feed pipe in both directions so worth considering all possible jobs that are easier with the boards up!
Just bought a 1910 terraced house and this is my first job with underfloor heating. Any pointers are always appreciated thanks.
Don't block any air bricks if you have a cellar.
I hope the void under your floors are well ventilated otherwise look out, we have just had to replace the entire floor joists insulation and deck as the builders did not install adequate ventilation and 200 x 50 joists had decayed and only 75mm was left in places after 12 years!
Haha reminds me of when I pulled up my floor recently to do this job and found that the original 1920's joists were daughtered up to replacements from about 1980. Both turned to dust when we pulled on them. The air brick had been blocked up for at least 70 years by the looks of it. ;0 They went to the trouble of replacing the joists but never bothered to check ventilation or figure out why the originals had dry rotted. We bricked up the fireplace and put an air brick in below the insulation level and replaced all the joists with reclaimed timber. Treated the ends etc. Solid as now. Last another 100 years no question.
I’m fairly sure he mentions in the tutorial that cleaning and ensuring the air vents are free of any debris or blockages.
@@jixuscrixus1967 someone obviously commented without watching the vid as he mentions it loads!
How are you supposed to ventilate the void under the floor?
@@sali8312 installing airbricks allowing the air from outdoors to flow under the floors preventing damp.
Exactly what I came to RUclips for i just bought a house with a suspended floor possibly 1950s an really wanted to insulate the floor now I’ve watched your video I have not only learned a lot (discovered a new tool pallet buster ) I’m even more confident of doing it thanks very much for taking your time to do this video it’s much appreciated
Been there done that. In 2017 I removed all the boards at one time, cleaned out and vacuumed underneath but then put a breathable membrane "up and over the joists" sealing in at edges then laid in sheeps wool insulation and put a new floor down. Stank like a barn for 6 months (not thereafter) but the insulation and sound proofing that it provided is on another level.
I'm planning to do the same in a few months so it's good to hear it makes a difference since I was a little worried that it wouldn't be worth the hassle.
@@elobiretv VERY much worth it if you do it properly. NO draughts, silent, breathable and the house warms up so quickly it's un-real. Huge reduction in heating bills. It's more work than using Celotex. As I have wood flooring, If I had my time again I would have considered running tubing underfloor as central heating and warming the whole floor area rather than radiators but that is another discussion. Hope this helps.
Did you put a DPM over the top after or just the single breathable membrane underneath to hold?
Thanks
Thank you! 👍🤘
It always amazes me how well those cut nails hold! They even seem to work on brick, holding skirting board on, but I have never managed to do that.
They nailed into a propeller pad hammered into brickwork joint 🤔👍
When removing nails from joists, I always give them a whack with a hammer first - it drives them slightly further in, but it also breaks the bond between the nail and the wood which has formed over decades, which makes pulling them out a lot easier.
Good tip! 👍
Wouldn't PIR being none breathable trap moisture therefore damp and rotten joists?
Excellent video. Nice to see a builder cleaning out under the floor, it's usually used as a disposal area. Most important to seal all gaps so drafts can't get through particularly round the walls which some people forget about and the wind whistles in under the skirting boards.
Thank you for the good guidance. Best not to cut the Ecotherm outside on the grass though. It won't break down in the environment. Better to cut it somewhere you can sweep it up or collect it afterwards. Technically polyisocyanurate is recyclable, (but left over sawings won't be), but otherwise it might go to an energy from waste plant, (or landfill).
I’d personally use a multi tool on the first floorboard so the cut doesn’t overlap and then circular saw the tongue & groove parts sections. The boards lift pretty well that way and virtually no damage. I’d also try to stagger the cuts so the cuts are all in a line, if that makes sense.
Thanks for the video though 👍🏻
How architects differ. Mine advised not to use PIR but to sling a breathable membrane on the underside of the joists then fill with 200mm of minimal wool. Fortunately, there was sufficient crawl space to get underneath and staple the membrane securely. Apparently this method is used frequently when restoring listed buildings.
I think there's a number of methods depending on building age, crawl space size etc. There's some best practice stuff here: www.gov.uk/government/publications/insulating-suspended-timber-floors-best-practice
'
"The Floor Board Fairies"🤣. Another step forward Andy. Well done!
Thank you! Wish there really were floor board fairies. 🤣
@@GosforthHandyman 🤣🤣🤣Crikey, I bet....3 days to do two rooms! I am sure it will be worth it. My house has solid floors and when I came to live here it had old ...but clean wool shoddy underlay. Brilliant stuff.
I did this when I moved into my bungalow late 2014, and put DPM on the subfloor to prevent moisture from the ground before keying in the insulation , cleaned up all the crap from the previous tradesmans work aswell,renewed the old floor boards for 22mm Caber floor....job done 👍
Hi did you just lay the DPM on the floor and that's it ? Thanks
As someone who's had many hurts, PPE is an must. Totally changed the way I work, and my comfort levels 👍👍
The exterior walls and floor joists are thermal bridges, even if you insulate the outside of the walls they are in contact with moving air bellow the floor allowing heat to transfer from inside the room down the wall, also through the flooroards through the joists, so the room is still losing heat
When the floor boards are up it would have been a great time to run any new wiring for a 'smart house' , new sockets or a security system .
I've been watching for about two years now and I have to say that the quality of the videos has improved. You've gone from really good content to magnificent content. I don't usually notice music in videos but I did here. I like it. If you've recently changed to the format, please do more. If this is consistent with prior vlogs, please accept my apologies for not noticing, and keep up the good work (phrase stolen from Essential Craftsman)!
Thanks - really appreciated! It's proportional to how much time I have for the edit. So now we're a bit further on with the reno I can take a bit longer making the edit nice. Next: More and better B-roll as I never get time for this. 👍😁
I managed some of my floors from underneath. This method is my next one for rooms with shallow crawl space.
Super job, well done. I like your attention to detail and thoroughness.
Cheers!
In the middle to doing this to my 1950s house. I'm putting down an airtighness membrane over the insulation before I put the boards back.
Great job - I would never have even thought of doing this to my 1920's house, but might have a go now if I feel brave enough
Exactly the problem I had when I insulated my ceiling - joists that hardly any of which were parallel. Took ferkin' ages.
Yup, takes forever. Not a single parallel joist. 😢🤣
there should be a layer of breather membrane installed prior to installing the PIR, then the joists taped to act as a VCL. Without these any moisture going in between the PIR and the joists will ruin the joists.
I would keep the newspaper clipping and frame it as part of journey of the renovation 👍🏽
Have done - got a little scrapbook going! 👍
Only if Newcastle won .. otherwise you nar bin it
Hi Andy, when I did mine I put the central heating pipes below joists so I didn't have to cut grooves out of insulation.
Tip for those impossible nails: The large curved back of full sized, vise grip pliers make an excellent fulcrum for pulling fasteners. You can *pull* out screws if you want to. Nails are usually easy. Even if you just have a few mm exposed from a broken nail you can still lock on and roll the pliers against the wood to pull almost anything. For the really hard ones, or brittle materials, you'll pull a few mm, then release and grab at wood level again, so you don't break the fastener off and make things worse.
Defo! It's gripping the head of cut clasp nails that's the challenge. 👍😁
Did this and works a treat👍
Use that Stanley Wonderbar to wedge under the visegrip in order to withdraw the nail vertically without having to bend the nail.
Wow, that is a lot of tedious work. Nice job!
i use a UV pen to mark boards with pipes or cables under
You do such a careful, neat job on things that don't show, so only your RUclips followers will know! Well, perhaps a workman 100 years from now may have reason to take up the floor and will appreciate the workmanship.
Cheers Bob - appreciated! 👍
Thanks so much for this. Was lining up the job myself but it's clear that 1) it's too big a job and 2) as i want to retain the existing floorboards, i'm better off just leaving it as it is for now.
Just insulated a 100 year old kitchen extension on a house. I found a RUclips video on cutting insulation where a large scraper has one side and the front edge ground to razor sharp with a grinder.
Mark board, use 2 or 3 inch straight edge to run the scraper at a perfect 90 degree. Once scored in by around an inch, throw straight edge to one side and run blade through by drawing it towards you with increasingpressure.
The best part being thar using a wide blade, the cut remains straight right through once started as board holds blade straight and NO MESS.
It worked a treat and with practice, really quick with perfect straight and smooth edges ideal for squeezing in.
The sharpened front edge can be used as a trim knife to assist inaccuracies in floor boards and joists as will as cutting out obstructions.
The bigger the scraper the better, ONLY grind one side and mark it as I did both and managed to slice a finger when pressing it down without thinking. This leaves one side safe to touch and push in for deeper cuts..
Lee do u have the link?
@@BoxerfanUK you mean for cutting?
ruclips.net/video/1cv46GuniIY/видео.html
Not sure this is same video but same idea. I sharpened a wider scraper than shown but either should work. Just get it razor sharp but watch your fingers, especially slicing in.
Awesome I wish my downstairs floor wasn’t concrete or I would be doing the same I bet it makes a huge difference
Cheers! Should make a big difference. With concrete you'd need to dig it up and re-screed with insulation. 👍
@@GosforthHandyman I just did what you have done last but year, bought mine ripped it back to brick and its done now so that won’t be happening now lol. I tore mine apart then lockdown happened and I was living there in one room and I had to buy 35 bags of plaster from gumtree for £20 a bag because there wasn’t any anywhere
Oh no! The materials shortage is turning in to a big problem. Our whole extension might need to be postponed. Heard about the plaster thing - crazy. 🙄
@@GosforthHandyman I hope you don’t get delayed to much I want to watch the progress 👍
Just been chatting to building control. They tell me that I need to make sure that the insulation is compressed against the underside of the floor, otherwise the warm air will simply wash away though the the smallest gap between the floor & insulation, making the insulation have no effect. Your boards were not touching, so what did you do about stopping this convection path?
They said that this doesn't matter in a loft because the insulation always falls/compresses tight to the ceiling, but the opposite occurs under floor.
The batterns where installed so that the top of the insulation was flush with the underside of the floor boards. Your never goinf to get it compressed. Even after installation you will never get full compression with constant walking g and furniture as this will slightly displace it anyway.
@@nathancurtis2585 Good point and explained in my other post. That's where they suggested a sprung batten to always push the PIR up against the underside of the floor. The walking on the floor will not displace the PIR at the joist. The PIR will flex with the floor between joists and spring back up with the board. Imagine a curved PLY bed slat screwed under across 2 joists with the centre permanently pushing the PIR up. An alternative is to seal the gap at the ends of each board.
The springiness of this particular video installation will be compromised by the lack of tong & groove / damage that would normally act to improve support via neighbouring floor boards, but singularly the will flex more. Hope this helps.
My question is what about draft? There as a many holes in between the pir as there are between floor boards. The warm air is going to seep out of there fast. I have put a damp proof membrane between pir and floorboards to stop any convection.
I would have woodworm treated the timbers, whether it needed it or not,( precaution ) I've always been accused of going over top on thing.
It's a bit of a gamble since you never know if the treatment is going to eat away at the 100 year old bitumen DPC. 👍
@@GosforthHandyman
I,ve had no issue with water base treatment.
You should also employ a fire marshal just in case, ya know 🤪🤪🤪
Great video, one extra tip is to fire the brad nails in at opposing angles, makes the pull-out retention much better especially with brads. 👍🏻
Also, expanding foam (using a gun for control) works great to stick the ends of PIR together, and along the batons if dropping the PIR from the top to seal.
Love it - and sounded like you enjoyed doing the job too! Shout out to your new massive dust pan & brush - two videos in a row. Spied them in Screwfix...impulse purchase incoming!
Best dustpan and brush I've ever owned! 🤣
Just a thought and to add a degree of crazy...
Under cut both dimensions by a half inch. Float it on your nailer sticks. FOAM a quarter inch gap all around. Then, there is no air gap in those imperfect hand saw cuts. Not that you had many. I know i do! Cheers.
I'm ambivalent about drafts. I know they are not good when it comes to energy efficiency and cost but they have saved our lives in the past. We once rented a place that had 2 appliances sending out carbon monoxide, unkown to us, one gas water heater in the bathroom and the living room gas fire. There was no central heating. Probably the only reason we survived was the draftiness of the flat. Where we live now is also somewhat drafty but when one family member in the house had Covid, no one else caught it.
Only breathable insulation should be used in the old sub floor. The timbers will sweat and over time will rot. Same problem as using spray foam insulation in the loft. It prevents air getting to the timber to keep them dry
Hi Andy, Great video, i have been following you for a while and you have helped with my renovation works. I do have a question, how close to the internal/external walls should the insulation be? how can i stop draughts coming up at the ends?
A Response would be gratefully appreciated.
1 year on, was it worth the time/expense ? I only ask as we moved into a bungalow where the only room which is a problem is the master bedroom with three outside walls with a big bay window. Next job is to install insulated plasterboard and possibly the floor .
This is a really good video bud : ) ... one thing though, it is important to also check drains prior to installing insulation as the moisture balance can get tipped in a floor by adding insulation, and it isn't unusual for timber decay or woodworm to pop up in the future.
I was going to pour vermiculite into the void (half fill) , would this be better for the timber. Also install black hole wall vents?
@@LabRat6619 personally I can’t see how that would any difference to be honest 👍
Is the crawlspace heated? Now that the floor is insulated, will the joists be kept dry after a period of rain and high humidity?
A great video, Andy. You are so knowledgeable and I appreciate you sharing. My son put a nail 40mm into his right foot yesterday. He tells me he’s finding stairs a challenge so no ‘Ray of sunshine’ smiley face today.
Cheers Ray! Oh no! Good excuse for a break. It's amazing how a split second mishap can grind work to a halt.
Router groves in insulation on top side and put warm radiator pipes on top would make a massive difference and minimise pipes freezing in winter
I've recently insulated all our floors with rockwool + Floorquilt By YBS main reason was fitting underfloor heating and it needed doing anyone doing this the floorquilt is well worth it as a secondary layer
I like your method for fitting that insulation. I have a cat S60 thermal imaging mobile phone. I can see on my floor there are cold spots against the outside wall where the air bricks are positioned outside.
At least your floor joists are solidly in the wall or on hangers. When i did mine, they were just sitting on bricks and slate packers. Like yourself i used 75mm Cellotex, but i had to take up 95% of the floorboards (very narrow and solid red wood of some sort) . As i replaced the flooring with grade 5 flooring tongue and grooved sheeting. Also made sure all the old rubbish left behind by previous craftsmen (why don't they keep things tidy?) and plenty of air circulating beneath the insulation. I then used foil tape over the joists and insulation to remove any chance of draughts, with expanding foam around the outer walls. Even though i tried keeping the joists evenly apart, they were old and bent so cutting the insulation was very time consuming. Major DIY job for me but it is level and so much warmer. Really like your videos, enough detail without going over the top.
Fantastic stuff and cheers!
Absolute gold 🙏 Loving the methodical approach to this job. Lots of useful little tips to make sure you don’t miss the obvious. 😅 Cutting the end of the PIR boards at 45 degrees to help encourage good air flow-magic 🎉 I now feel confident enough to take this job on myself-thanks mate 👍
I used expanding foam to glue each insulating foam board/piece to each other. Seals any gaps ypu might get from bad cuts.
Nice long piece of 4x2 about 7ft will do for levering up those floor boards. Also, i’d say 70-80mm plenty thick as PIR. Only question is why wouldn’t you pin those battens to the underside of the joists? Looks like you have enough room to get a first fix nail gun in there at an angle which would be better anyway as skew nailing would better hold them long term. Just a thought anyway.
Do you sealant or tape the joints between each piece? Maybe it's worth putting a squirt of sealant on each edge so that there's a good seal when you push them together.
On new builds, extensions, I've seen tape used on the joints.
Since they sit on full length battens it's not really needed - I'd rather let the whole system breathe a little. 👍
Pir board is better than quilt in this application. The use of foil tape keeps out the odd draft to.
That puts the LABOUR in labour of love! Well done, brother. it's all in the details.
Cheers! Not a pleasant job but glad it's done. 👍
@@GosforthHandyman That would be satisfying to have knocked off the list, for sure!
I'm just about to get started with this job. What size of brad nails did you use to fix the battens? I am guessing something like 40-50mm (don't know much about nail gauges). I'll be tackling it all from underneath as there is enough space down there to leave the floor intact.
In the 1920s, houses were built with adequate air flow underneath the flooring to prevent mould and rot in the timbers as well as helping to create a draught to draw the coal fires. There is a modern principle in thermal insulation where you need to meet the thermal triangle of thermal, air flow and moisture. Using hydrophobic insulation prevents the flow of air and contributes to moisture, which encourages the growth of mould and rot. Instead, install a vapour barrier to prevent any moisture from the soil, then add a breathable airtight membrane to prevent wind-washing and let any moisture escape from the joists. Next use a high density hygroscopic insulation, such as sheep's wool, jute or wood fibre. Finally, add a vapour control layer before re-laying floorboards.
Wow.....do you have a RUclips channel? I have a Victorian terrace house and 6ft height in the cellar, can only access in by a small trapdoor in my back room. I need to insulate under there sometime this year, as the heating Bill's are on the rise. I need to cut down the cost! I would love to able to see some ideas on how I can do this job myself.
I'm thinking, if this was done to a floor upstairs- it would also improve insulation to the room downstairs too.
Does that sound right to anyone, because we need to resecure some floorboards in the bedroom (and the living room is freezing) so while the floors up anyway.... Wht do you think?
Some people might suggest laying a vapour barrier down before re-fixing the floorboards. What are your thoughts on that? Nice job by the way!
It is recommended
Then you are taking all the floorboards up I guess. I am planning to do this and am confused over the need for a vapour barrier now.
The insulation acts as a vapour barrier here, taping over the joists and between insulation would make it continuous. Is it worth it when you'd still have bigger/harder-to-seal gaps around the edges? In his case he said he'd add a hardwood layer over the top too.
It's not recommended but it's optional for additional air-tightness. Not really needed in this scenario as would be a nightmare to fit. Useful info here: www.gov.uk/government/publications/insulating-suspended-timber-floors-best-practice
@@GosforthHandyman They really are a nightmare to fit and make it a nightmare getting your floor boards back down at anything approaching level imho.
I have a comment. I feel for your knees and back! I've been working on my similar looking home, in the attic, where I can't stand. Just killer on the body! Great job and thanks for sharing!
Surely you should have sealed the celotex boards together and against the joists? All those gaps will allow cold air through and around the celotex, greatly reducing the insulating efficiency!
supposed to be a small gap between top of celotex and underside of floorboards to reflect heat
I've lifted a few floors in my time and it never ceased to amaze me how many revealed piles of pipe/cable offcuts mortar and other debris.Just plain lazy and untidy.We think alike Andy!
Yup, hate leaving it like that. Cheers!
Have you ever considered using foamed glass to fill voids instead of PIR boards? I am always concerned about moisture condensing especially between joists and insulation boards. Wondering what is humidity level before and after installing insulation. I know you did good job on air bricks but still remember how many old building were damaged just by cement based plaster or pointing on bricks.
So want to do this to my house built in 2000. The bedroom over the garage has no insulation under the floor but my floor is t&g chipboard. I already sealed the edges which made a big difference.
Great stuff! I'm sure in 2000 it was a requirement to have insulation over a garage. 👍
I'm gonna need to do this from the crawl space. Pain in the backside, but will help a lot with the ground floor.
instead of timber battens cut into small pieces could you use a flexible plastic angle trim that could be fixed in long lengths, under the floor boards..??
Do you feel a big difference after these two years?thanks
This brilliant.. Instead of the baton, I would use Expamet Steel Angle bead. If your joist is 100cm you then should be able to fit it in-between if using the steel angle bead.
Be interesting to see if it makes a big difference acoustically? I did mine from the crawlspace below in Rockwool. It was not pleasant!!!
I don't think it would make much acoustic difference. 👍
A good job but I’d be concerned as to air flow around the timbers and possible problems…
What was the cost? Also, great job
use a nail punch first to knock the nails as far in as you can , then the boards lift out cleanly with no damage
Hey great work. How would you secure all boards to avoid squeaking in 5-10 years ? And any tips on removing multiple layers of old underlays ?
Did almost exactly the same to one of rooms, plans to do the others soon. I foamed gaps around the edges and used aluminium tape on all joins.
That"s the proper way, all joins and gaps, regardless how small, should be finished air tight, just a 1mm gap between two pieces in several spots can affect the effectiveness of the insulation by 25%.
And should a damp proof membrane between the insulation and boards or between boards and new flooring be used?
The 1mm gap / 25% thing is a myth - think about wearing a winter coat and having a 1mm gap - are you 25% colder? I would foam edges of big gaps if needed. Tape isn't part of the best practice guide but I guess is probably wouldn't do any harm: www.gov.uk/government/publications/insulating-suspended-timber-floors-best-practice
@@GosforthHandyman A winter coat? Pfft, I expect someone from the North of England not to know the answer to that question. If you'd said "a hole in your t-shirt", that'd be a better anology.
As it happens though, I have a hoodie I sometimes wear when it's -2C or whatever, and it has these ventilation holes (maybe 2mm diameter) in the back. The draught that comes through them is intense, and I've actually tried covering them up for a bit of an experiment (with tape, but not in public, I'm not a total weirdo) and it significantly improved the heat retention! I was surprised. I don't believe the 25% thing. I do like the look of the gapotape product however, it looks the part, but I'm guessing it's horrendously expensive.
Does this insulation not push and water / damp through to the walls ?
I really want to do this but having read that the foil membrane can be a cold surface for condensation, I am concerned I will introduce water issues. Don't you have any concerns over that? Even if I is well ventilated, so long as their is moisture in the air and the foil a cold surface, you could be looking at months of wetness every year that will eventually cause damage
The dew point is in the middle of the PIR. The top foil will be at room temperature. The bottom foil will be at outside temperature. Unlikely you’ll get condensation on the foil itself.
I ended up using a more expensive product with a fibre glass skin. Has made a tremendous difference to the room temp
I wish I'd seen this a few years ago! I learned some of your lessons for myself in a Jesmond terrace, but that's a *much* nicer job than I've done so far. At least the hallways and kitchen will better, thanks to this video :-)
Cheers and best of luck for your final bits! Some lovely houses in Jesmond - worked in many of them! 👍
Could I use similar method to Sound Proof the floor a little on 1st floor? Just ripped off the carpets to fit wooden flooring. While I am here I'd like to sound proof it a bit since it'll be a kids room :)
Amazing video. Thanks for sharing!
To be honest with you,you’re the first guy I’ve seen doing insulation in this manner. Normally it’s to expensive to have a man doing all this work for days on end . What happens in the real world you take a chainsaw around the outside edge and cut the lot. Fill it with insulation and put in a new solid floor.
I thought a 50mm air gap is required between the PIR board and floor board to prevent thermal bridging?
In Norway we insulate 300 mill yo the ground. Airtight floir is also important
Bet the mitre fix says spray the activator before using the glue it stops it going white
Was there a particular reason why you didn't use spray foam to bond the insulation boards to each other and to the joists? That way the floor would've been air tight.