Underfloor Insulation Insulating The Living Room Floor And Save Money On Energy Bills

[@DavidMarfe]

Don't Forget To Subscribe And Smash That 👍 Button

[@shahdrah]

This is a must to DIY job for any house more than 50 years old with draft from the ground floor space. Should be a huge heat saver. Don't know why this isn't mentioned more.

[@davidramsay6142]

You now have floorboards sandwiched between two foil vapour impermeable layers.... not good practice. If water finds its way under it could be trapped, yes joist is a path but a very slow one. I do this job with rockwool held up with garden fabric stapled under joists. Does not sag or degenerate and allows water and vapour through. Much cheaper than PIR and very effective. I do put 1 foot of PIR around perimeter external walls.

[@MacdonaldEdinburghElectrical]

Hey I’m looking to insulate my crawl space using wool. Should I hold it with a fabric?

[@andybrace4983]

Would of been nice to replace carpet after all that

[@markosthomadakis9256]

if you are British you know the answer mate

[@user-sj2ny2qi4x]

He ran out of money I think or he's gonna do that in another video haha.

[@adamosantonio1499]

It wos persian carpet bro.

[@jamiem7649]

Ha ha. Was thinking the same thing

[@aaronvallejo8220]

I dug out my 1910 floor for a little wiggle room and then installed R29 batts in those spaces between the floor joists. I then held it in place with 1" tinfoil foam board installed with large washers and 2" screws. I then spray foamed all seams and cut them flush. Then with aluminum tape over all seams it creates a single insulated R35 barrier under the old house. Finally warm and renewably powered.

[@billvojtech5686]

I noticed some pipes under the floor had insulation on them, I assume to help keep them from freezing. If the crawl space isn't heated, the only heat source was what was coming through the floor. The crawl space may be colder now. Maybe put some heat tape on the pipes?

[@DavidMarfe]

I insulated pipes and taped the joints as they are central heating pipes and there is no point of heating underneath the house because of not wrapping the pipes also I did it for all pipes underneath the house. You want your heating system to only let the heat out through the radiators for maximum efficiency your boiler will come on less if this level of work is done.

[@Thomas63r2]

What many people do not know is that heat loss through the floor is second to that from the ceiling. Fixing floor insulation issues is more important than updating windows.

[@DavidMarfe]

It’s also more cost effective costed £300 in parts and materials to do the floor myself it costed me £1600 to do the window myself behind me.

[@johnevans7389]

should of put some battens under the joists to support the cellotex.

[@Mourad1EL]

The problem with PIR insulation is that it's not breathable, meaning condensation, damp and rotten joists, especially in old builds. I would use mineral wool even thought wouldn't get the same U value as with the PIR .

[@explorewithant]

That foil underlay is for laminate flooring I thought

[@rlindsay23]

Great upload! Thanks for sharing!

[@LabRat6619]

Hope those Crocs have steel toe cap?

[@DavidMarfe]

Let’s be honest no one messes with a croc 🐊

[@OstretsovArtem]

I thought before the video working in sandals is only our ancient Russian tradition)

[@grolfe3210]

You should check and make sure the under floor vents are still there and working. You should insulate all the pipes that will now be in the unheated underfloor area. Personally I would not use celotex boards. They are hugely expensive and in an old house will not bring the overall insulation up to modern standards. English Heritage recommend you use rockwool or even just loft insulation sitting in a netting support. This also keeps a little air flow around the timbers and stops them getting condensation build up. The wool insulation is not quite as good but 100mm under a floor is very acceptable. You will never recoup the cost of celotex. Also wool can be fitted in half the time and you can often do it by just lifting every 5th board.

[@DavidMarfe]

It was done 7 years ago I check last year everything is fine all the pipe were insulated when it was done to not only save energy but to also reduced/stop condensation on the pipes it costed £300 in 2017 for materials and I got the money back by last year I didn’t have the heating on at all apart from maybe apart from three days house stay 21c the whole winter helped by cooking and television and other household appliances producing heat.

[@liamg9846]

Where’s the breathable membrane underneath the joists before your boards?

[@samuelhara4874]

Hi. How does that work? What purpose does it serve? Thanks

[@fanfeck2844]

@@samuelhara4874 stops cold moist air rotting your joists, but the cavity will be vented with airbricks, so shouldn’t be a problem

[@arabianmenace527]

The breathable membrane is to hold the other type of insulation (rock wool or fibre insulation)... however he should have used a damp proof membrane over the joist and celotex to the side of the skirting.

[@wainwrightay]

Nice video. However those floor boards will be nice and wet soon with the lack of ventilated air passing over the battens. There may be a small amount going through the tiny brick holes on the batten pads, but that will not be sufficient. Are your air bricks clear?

[@DavidMarfe]

The whole floor is vented air passes through it only the joist are filled the ground below is full of air passing through

[@eternalfizzer]

That's a long hard day's labour. If you're planning to reuse the boards, drop a blob of white paint on each at the start, then number them with a marker before you pull them.

[@jeanpaul2653]

im guessing this is to help when you place them back down?

[@eternalfizzer]

Exactly - no point in throwing out nice dry lumber that's already cut to fit. I'm just doing the same with my (uninsulated) extension. Saves me a trip to the lumberyard.

[@heliotropezzz333]

Do the air bricks still do their job effectively after this insulation?

[@DavidMarfe]

Yes you don’t block them it needs to circle late in the void as moisture will build up.

[@heliotropezzz333]

@@DavidMarfe Circulate?

[@jacekkuc916]

I dont want to cover wood, can i put plywood on top of insulation than thermal tape and on top wooden floor?

[@adamosantonio1499]

Yo🙋🏻‍♂️.what about after kingspan lay intello plus membrane,,? Is that needed, or just like you do is fine enough.? Thanks for shering 👍 🍻

[@falfield]

Nice video and interesting to see. But did you not worry about using insulation as thick as your joists, which then blocked up the air gaps over your sleeper walls, and so trapped air under the centre of the room? I've always understood that cross-ventilation is vital - am I missing some detail here?

[@samueldeakin2902]

Dry rot ..

[@falfield]

@@samueldeakin2902 Yes, I know that's the risk - the question is what he did about it. I've done some UF insulation in a site with some similarities, and knocked some bricks out of the sleeper walls and an extra hole in the outside wall. But maybe his house is on the top of a hill, open to the prevailing wind - mine wasn't.

[@thisisitrecords2539]

He should have used 40mm foam, at least he still would have a air gap!

[@adventtrooper]

There's holes in the sleeper walls for cross ventilation.

[@falfield]

@@adventtrooper Thanks, and well done for spotting this - where did you see it? I looked, but without labouring through the whole video again, I couldn't see any. Besides, when the house was built, why did they bother building sleeper walls with such gaps, given that above the wall-plates and between the joists was room for such air flow as would gladden the heart of any buildings inspector? In my house's sleeper walls, there were no gaps till I made them.

[@curryhouse1377]

Good Job...How many days total you spend to finish?

[@rossMoHaX]

Is it just friction which holds some of the insulation boards in place? Wont they sag down with time?

[@DavidMarfe]

And a cross section.

[@TheSmithyt]

Wow !! All that work done in under 9 minutes you must be loaded 😂😂

[@DavidMarfe]

Yeah my back hurts still to this day haha

[@dzmalekvali1110]

No batons under the insulations??

[@livingladolcevita7318]

I was wondering that as well. I did mine in a similar way but put batons down just in case the insulation falls through

[@larax015]

Would be a vapour barrier unnecessary on the warmside?

[@livingladolcevita7318]

see above

[@alexmac101]

Great video, I’m planning on doing the same. The way that you cut the Celotex so it just fits in between the joists is enough to hold it up? No batons underneath or something like that?

[@tgk300xx4]

alexmac101 personally I think that the way this has been done in this video is very poor. They should of attached battens to the underside of the joists and then foamed and gaps. So yes, do our battens on the bottom of the joists.

[@WatchingTheo]

My building officer advised to use batons under the joists to support the insulation, but also to leave a 20mm gap at the top of the joists

[@stewartno9118]

Theo

[@liamg9846]

Also a breathable membrane underneath the joists before insulation. Should have vapour taped the gaps before putting floor boards down again

[@vinceking7878]

Won't this trap damp?

[@DavidMarfe]

+vince King no as the airbrick are still open so air pass through underneath allowing the void to breath.

[@vinceking7878]

@@DavidMarfeyes, but what about between the insulation and the beams?

[@cgavin1]

@@vinceking7878 Its not something you will need to worry about within your lifetime.

[@quench1234]

Hi 🙋‍♂️ how is the floor now ! Is it cold to the touch still is it comfortable to walk on without feeling cold ? I’ve got this too do just wondering if it will make much difference as our floors are freezing 🥶 with the 12” void and then floorboard only even with our 10mm underlay and thick carpet it’s still cold Many thanks

[@DavidMarfe]

Its on my thermo reader im getting 18c from the floor and it's nice to walk on spare foot. I haven't done the kitchen yet and that gives me cold feet

[@robertotheo]

Hi, Thanks for the great video! Can I ask how did you deal with having a damp proof course ???? I want to do exactly as you did but I've also seen people remove the skirting boards and have at least 7.5cm DPM running behind it. If I'm honest I'm not feeling talking off the skirting and then the joys of repairing all the walls What're your thoughts? Thanks in advance Gary

[@NN-eg7qh]

I watch someone put a layer of plastic sheet for damp proof before

[@xxmisiekxxable]

In this type of building dpc is below joists level so no need to do anything behind skirtings. It wouldn't make any difference.

[@kuk3411]

I think Gary means a vapour control layer. Without one, any water carried in the warm air from the room would condense if it gets to the cold part underneath. (This is because warm air and cold air typically carry different amounts of water) This would be fine before as the cold air carries it away but not once you have insulation under there. This is because once you add insulation, you move the point where warm and cold air can meet (the dew point) So now the dew point is likely to be half way up the side of the wooden joists. You don’t want warm air condensing half way down your wooden joists as this can cause damp issues, rot, mould and woodworm. The solution for this is to stop moisture getting down there from the warm room. You can use a layer typically used for roofing but they’re quite expensive.. you could even just use a basic damp proof plastic (the type that is usually used underneath a slab of concrete before a pour) but basically anything that is not vapour permeable. You would then bring that vapour control layer up the sides of the wall a few centimetres and tape it to the wall. You then cover that with the skirting. You have to make sure that the vapour control layer is the warm (room) side of the insulation for it to work.

[@SHINdanny]

"Insulating The Living Room Floor And Save money" ...to purchase a belt ;)

[@DavidMarfe]

Thanks for watching

[@Shaxxie]

Hey was a bit of excitement! 😂

[@lgenius5593]

and to purchase safety boots ? :)

[@highland-oldgit]

Nice. I'm going to do this and thought I would need batons perpendicular to the joists but it looks like the insulation is in so tight that it can't fall through ?

[@DavidMarfe]

It’s sitting on a cross section so it can’t but yes if you get a friction like I did fit it won’t move as well

[@Scoby0075]

Hey there I’m on the road I should have

[@Scoby0075]

Hnb is so pretty 🤩 thank

[@DavidMarfe]

Huh 🤔

[@MM2009]

No point to insulate with such an expensive insulation if you don't insulate timber, foil faced also not required if no air gap left.

[@becauseimhappyxx7094]

If I don't want to lift my floor boards. Can I just use the thermal underlay?

[@DavidMarfe]

Yeah it all depend on the level of u value you want to achieve and energy savings.

[@becauseimhappyxx7094]

@@DavidMarfe OK thank you.

[@hamidbazmi7948]

Hi, what is the timber size please? 4x2?

[@cormachall8555]

Any advice on where to purchase insulation boards in the UK? is online or at merchants a better option?

[@DavidMarfe]

I currently use BMD insulation as my supplier

[@mrdee0]

Wondering about condensation and rotting of the joists. Is that going to happen?

[@DavidMarfe]

+mrdee0 only if you block the air bricks

[@DavidBrock-e8l]

Should have sanded the boards : can’t believe you put that old carpet back down afterwards !

[@wind5250]

You shouldn't have a vapor barrier under your floor it traps condensation caused by the difference between hot and cold . I would have pulled all the old board's , insulated the space between then replaced the subfloor with either insulated osb or standard plywood sheets .

[@vinceking7878]

Please explain

[@andrewsmall6568]

Does this really make much difference if the rest of the house is standard 1920`s build?

[@DavidMarfe]

Well if you do the whole floor downstairs as well as pipe work and convert the loft to very good standard double glazing front and back and of course if you house has a porch roof that is tiled and runs along the full length of the house like mine then that also needs to be insulated and you have a bay window the ceiling isn’t insulated so do that to and your notice a big increase in the amount of heat your house retains my dinning room which I did first doesn’t need the radiator on now during the winter after 5 minutes the room is hot. I’ve got to fit thermostat valves on the radiators now to improve efficiency so they switch off when the room reaches the perfect temperature.

[@cgavin1]

If you don't do this you basically have your entire house venting directly outside at ground level. So your central heating basically doesn't work. Not kidding, I have had an 8kw wood burner on full bore in an adjoining room and it was still freezing. Sealing the floor makes a HUGE difference in heat retention even if the rest of the house is leaky af.

[@dzmalekvali1110]

Should have numbered your floor boards..

[@roni2977]

Doesnt that make the joist soft, someone told me that air doesnt each them and you start getting bouncy floors.. 🤷‍♂️

[@BlueGamerDude]

why did you hide that beautiful wood flooring :(

[@jamespears1731]

For the same reason they installed in the insulation - it was bloody cold!

[@BlueGamerDude]

@@jamespears1731 not after the insulation?

[@tgk300xx4]

BlueGamer Dude Beacuse it’s horrible.

[@TrollBenable]

​@@BlueGamerDude house insulation doesnt mean warm it just means things stay warmer more easily. carpets retain warmth much better than wood. so carpets feel nicer all around even if you have the heating completely off because theyre much more effective at retaining heat.

[@BlueGamerDude]

@@TrollBenable if its cold the carpet will still be cold lol

[@cheerio8096]

It would be easier to just install the insulation and venting from under the house

[@Elektrifekt]

How much does this cost?

[@cgavin1]

Eleven million pounds. Twelve in London.

[@livingladolcevita7318]

If you live near Caerphilly in Wales there is a place that does seconds. I managed to get enough, 90mm thick, to do 2 rooms for about £100 with delivery

[@livingladolcevita7318]

I went to Trecenydd business parc, Caerphilly. Been a long time, when I can get out will have to check if it is still there

[@TinTaBraSS777]

молодцы )

[@butcher520]

I hope that man has bought a belt for his trousers

[@DavidMarfe]

That’s losing weight for you burnt calories at an alarming rate. Doing this job.

[@shirleylyle7135]

Hi I maybe getting help,from the Green homes Grant (eon) scheme to insulate my down stairs rooms, as the floors are freezing. It's good to see beforehand how it's done, so they don't put any old 'crap' down and now ,I've got this video to compare, and see what materials you use.. hopefully I won't get "ripped off" Thanks

[@express375]

Patreon link to donate for belt?

[@trevor44ish]

Not sure that removing the cross noggins was a good idea. They are there for a reason and not just to prevent joist twist.

[@DavidMarfe]

Errr they were never there in the first place.

[@g-htr]

Hi David, nice video! I have oak flooring and it is really cold on your feet, and so thinking about doing something similar. I will be going underneath the floor as I have 4-5 feet crawl space and dont want to disturb the wood from above. When doing the job from underneath, would you recommend colotex or a hung net with rock wool? I keep hearing conflicting recommendations for both. Thanks

[@aaronvallejo8220]

I crawled under my floor once I dug out 2 feet for wiggle room. I then installed R29 insulating batts and held it all up with 1" of tinfoil foam board with large washers and 2" screws. I spray foamed all seams and when dry I cut it flush and put on the aluminum tape over all seams. This created a single insulated R35 floor. My old house is now finally warm.

[@danielpeake2691]

hi @Greg-hunter, what did you go for in the end? your situation with the cold oak floors sounds just like ours currently. thikning of doing this

[@g-htr]

@@danielpeake2691I hung rock wool in the end, which was a real pain to do. If I could do it again I would have use something like kingspan or polystyrene sheets.

[@danielpeake2691]

@@g-htr I agree the kingspan looks easier. My quandary is if the rockwool is better for the joists, as the rockwool is surely more breathable? Or am I being daft 😂 I should probably pay a professional, but I don’t trust these insulation companies running as Ltd companies. That are liquidated by the time you start getting issues. Theyre nowhere to be seen now with the cavity wall insulation scandal

[@g-htr]

@@danielpeake2691whenever I see builders do an extension, they usually use kingspan or something like that between joints. I think you just need to have the foil facing up to the floorboards and that will stop the warm air making contact with the cold and making condensation, but definitely do some research as I’m not a builder or know your property. Good luck

[@DavidMarfe]

Watch my latest insulation video here kzbin.info/www/bejne/eWGXiqmdr5J7hNU

[@MrAnon-2024]

Loving your vids 👍 Really like the idea of the foil underlay as that will, I assume, also help with reducing the thermal bridge effect of the joists. Did you look into adding that ‘underlay’ across the top of the Celotex/joists then placing the floorboards over the top? I have a small concern that by ‘sandwiching’ the floorboards between, effectively, two vapour barriers, that any moisture in the floorboards would be trapped there. I may be worrying unduly about this but would appreciate your thoughts on this. Cheers 👍

[@DavidMarfe]

It couldn't be done underneath the floor boards on top of the Celotex boards plus the celotex boards have a reflective thermal surface and the boards stop moisture touching the floor boards and I left the floor boards for a week to settle before I laid the reflective under lay this stops the hot air and cold air underneath the floor from touching. so no condensation will form. Which is the biggest cause for rot and I engineered air intakes so the floor underneath breaths throw the air bricks so it will dry out any vapor and in the summer the temperature under the floor can get as high as 25C so it will be bone dry under there and the room will stay cooler. Got the l new loft to do next. and the first floor to do some work to. had a cowboy builder do the loft 10 years ago so ripping it all and starting with a clean sheet of paper. Thanks for your comment and thanks for watching.

[@MrAnon-2024]

DavidMarfe thanks for the feedback. I’m actually making a start tomorrow by lifting all the floorboards before starting the clean out the following day. I actually did our loft space a couple of years ago. Me and the better half cleared out all the old fibreglass insulation before laying Celotex (two layers) then boarding out. I then covered the underside of the roof with Airtec foil/bubble insulation fastened to the joists. I also got an electrician to renew all the electric cabling in the loft space. Hope you’ll be making videos of your loft project 😉

[@chrbx13]

Please share a tutorial

[@chrbx13]

Please share a tutorial

[@chrbx13]

Please share a tutorial

[@vivdoolan6846]

After all that work a lovely wooden floor was covered up with a really grotty old carpet.

[@AzH1988UK]

For the price of a new carpet I can't understand why you would go though all that effort and not lay a new one

[@DavidMarfe]

Because I wanted a stop gap for the moment until I either lay a new carpet or put a oak floor in.

[@nt7686]

I don't suppose you're based anywhere near Blackpool are you?

[@IJHougfhton]

that looks like a can of worms to do...…

[@cgavin1]

Nah its easy bro. I did one this last week and the whole job took about 4 hrs. I'm DIY not trade. 👍 I would suggest using some netting or battons under the insulation just to make sure it can't collapse once the house settles over time..

[@DavidMarfe]

Thank you so much for 60,000 views !!!

[@johnoleary9317]

75k now.inspirational Maybe 1 day new homes will come to your standard. Not just EPC inspect the one home the developer lets them

[@piotrkulpa8034]

So much work just to put ugly carpet at the end.

[@DavidMarfe]

The lady of the house didn’t want it gone.

[@DavidMarfe]

Check Out The Website www.davidmarfe.com/Videos.html

[@MM2009]

You have used 100mm PIR foam with a radiant barrier not providing the air gap - amazing... You covered everything with the planks, then you put another foam with a radiant barrier. NO MOISTURE BARRIER - SHIT JOB. What's the point in 100mm PIR foam when your floor joist is still bridging cold?

[@laurieh]

How are you supposed to insulate joists? Wood is a good insulator anyway

[@ndc982]

@@laurieh Well said, very true 👍

[@jonneym]

Two things. Why sweep and clean under the floor when it’s time consuming and unnecessary? Also it’s a suspended ground floor. If you have good underlay and a quality carpet down you will hardly notice an increase in warmth as heat rises. Heat in the home is mainly lost through the walls, windows and ceiling/roof. I feel there is very little to be gained from all this work. It makes me wonder how my NaN survived to 87 without all this BS

[@roni2977]

Same ugly carpet back on 👏🏼👏🏼

[@jipedowilliamson204]

One of the most frustrating videos on youtube

[@johnransby8912]

way too much detail, i don't need to watch every little detail. and not professional job either

[@DavidMarfe]

Thanks for watching!!!

[@lynngardiner227]

This would make next to no difference

[@DavidMarfe]

Well I don't get cold feet anymore and the room stays above 20C all night in the winter after the radiators been turned off after 7 hrs and before I did it dropped after 2 hrs so.........

[@gdr88]

@@DavidMarfe Any update 2 years on?

[@DavidMarfe]

I’m doing the loft at the moment but lagging the down stair pipes and insulating the floor has reduced the heating bill by £100 a year. So I only got two more years before I get my money back for doing the work.and then it actually will be saving money.

[@cgavin1]

It really does make a difference. If you have ever tried to sit in a room with a suspended floor you'll know that in winter it literally never gets warm. Not even with rads on full!

[@Largeone1968]

Sod the cost, it’s your home and comfort is everything. You can’t put a price on feeling warm and cosy in your residence.