Draught proof wooden floor.

tom1ie

Hi all,

looking for a bit of advice here, we are changing out floating laminate wooden floor at the minute in the downstairs of the house.

I’ve pulled up the laminate floor and the underlay and I’m back to the floorboards.

The floorboards have been lifted and had the T+G removed in some spots for wiring, plumbing etc and there is the potential for draughty to come up through those gaps.

I was thinking of:

laying plywood over the floorboards (the thinnest I can get- 6mm?)

laying the underlay over that

taping the joints in the underlay with air tightness tape

taping from the underlay up onto the wall behind where the skirting will be

laying the new laminate floor.

What do you guys reckon? Is there a better way of doing this or even a barrier I could roll out and use instead of plywood?

Any advice greatly appreciated!

DOCARCH

Sorry....closed by accident after editing thread title. Open again.

tom1ie

https://www.boards.ie/discussion/comment/121844307#Comment_121844307

Fair play docarch thanks.

I have posted in the DIY thread after i realised this one had been closed- is that ok?

DOCARCH

https://www.boards.ie/discussion/comment/121844503#Comment_121844503

Sure. Only reason for editing thread title was it originally said 'Fraught' rather than 'Draught'.

Back to the topic. What you are proposing above sounds generally fine, however replace underlay with an airtight membrane, like Pro Clima DA with associated tapes.

If floorboards messed up, simply consider replacing all with 18mm WBP or OSB3 (with airtight membrane over)?

Markcheese

Is there any insulation under the floorboards ,/ between the joists ?

If not , now might be the time...

tom1ie

https://www.boards.ie/discussion/comment/121847291#Comment_121847291

Yeah good shout.

Although would I not need the underlay on top of the membrane also?

I thought the underlay adds solidity and that solid feeling to a laminate floor? Laminate floor will be 12mm.

tom1ie

https://www.boards.ie/discussion/comment/121847313#Comment_121847313

Hi Mark- no there’s not and tbh I’d love to do it but I don’t have the budget or the time and with three kids a dog and a cat that keeps going missing under the floorboards, (just the cat not the kids and dog!), I think the airtight membrane is about the best I’ll get to!!

Shoog

If you can sacrifice some height then the solution that worked for us was;

-airtight barrier on floorboards

-25mm foil backed urethane board over top

-topped with 18mm OSB floorboards glued and floating

-underlay and final finish.

This is a days graft.

The vapour barrier taped behind skirting boards will get you most of the way there as it will kill the stack effect which is constantly been drawn up from the cold void below the floor. However without the insulation the floor can never really get above the outside temperature so will always feel cold. Cold feet means you all feel cold.

MicktheMan

https://www.boards.ie/discussion/comment/121847721#Comment_121847721

I second the sealed air tight membrane.

You could also do both the sealed air tight membrane and the underlay 6mm board.

tom1ie

https://www.boards.ie/discussion/comment/121847835#Comment_121847835

Yeah I’m thinking this.

I have the old underlay that I will reuse over the airtight membrane.

this is the old underlay:

https://mulveys.com/products/sonic-gold-sound-reduction-underlay-15sqm-roll/?gad_source=1&gclid=EAIaIQobChMItYzNhM7ahAMV15xQBh1hcgIdEAQYBSABEgJcv_D_BwE

Markcheese

If you use a staple gun to install the airtight membrane , you could follow the "depth" of joists ,and then just push in cheap rockwool insultion , you wont e lifting the floor boards again in a hurry,

Obviously you'll use more membrane too ,

tom1ie

https://www.boards.ie/discussion/comment/121852642#Comment_121852642

Yeah but I’d have to lift all the floorboards which I just won’t get a chance to do unfortunately.

Markcheese

https://www.boards.ie/discussion/comment/121852849#Comment_121852849

Ah ok , sorry , I thought you were already lifting all the floor boards - my bad ...

GlennaMaddy

consider heating film, a lovely warm floor makes a big difference. It can replace or compliment whatever room heating you have.

tom1ie

https://www.boards.ie/discussion/comment/121853606#Comment_121853606

What’s this now? 🤔

Also what are people’s thoughts on just using air tightness tape along the boards where the T+G is missing or damaged (I know this may be half arsed🤦‍♂️)

GlennaMaddy

There are a few similar systems, I ended up with the termofol system as I was able to get someone to fit and wire it, wholesaler website is https://termofol.ie/gallery/ ( they might sell direct, but they don't fit)

looksee

I can see the edges might need some seal but - just out of interest - why would the click laminate floor plus the thin 2 or 3mm insulation layer that is standard with laminate floors not keep out draughts?

loyatemu

https://www.boards.ie/discussion/comment/121847822#Comment_121847822

you have 2 floating floors on top of the floorboards? Or is the final finish carpet? Either way it seems like overkill - surely youd get 95% of the same effect with just airtight layer/decent underlay/laminate or carpet.

tom1ie

https://www.boards.ie/discussion/comment/121855863#Comment_121855863

It probably will to be honest!

Im just being a bit OTT I think.

I will definitely be using airtightness tape for jointing underlay and where the underlay meets the walls.

I just wanted to add another layer of draught protection underneath this.

Shoog

https://www.boards.ie/discussion/comment/121856211#Comment_121856211

Underlay is a few mills at best, what I suggest gets you 10mm of high quality insulation which will make a big difference.

When we did it we just painted the OSB.

Shoog

https://www.boards.ie/discussion/comment/121853719#Comment_121853719

Airtightness tape is expensive so this would likely work out far more expensive. Think €30.00 minimum per roll.

looksee

https://www.boards.ie/discussion/comment/121856852#Comment_121856852

I don't think you can put 10 or even 5mm underlay under laminate flooring, it would create too much bounce and crack the tongues.

10-10-20

https://www.boards.ie/discussion/comment/121858671#Comment_121858671

It's like walking on a planked footbridge. I wouldn't.

Shoog

https://www.boards.ie/discussion/comment/121858671#Comment_121858671

That is why you put down a glued t&g OSB subfloor before your final finish floor. Also urethane sheet has almost no given when there is a floating floor over it - it's not compressive at all.

If you think that 2mm of insulation is adequate then don't bother.

sirmixalot

I put 5mm gold down on 12mm laminate, worked fine for me. Also, get some expanding foam, fill gaps from floor to plasterboard where it meets the ground, should be a few cm distance, I then taped it all up again with sealant tape, all drafts are gone now from that room.

sirmixalot

https://www.boards.ie/discussion/comment/121856872#Comment_121856872

This stuff is great https://amzn.eu/d/fPw7qeN

tom1ie

https://www.boards.ie/discussion/comment/121858737#Comment_121858737

Yeah that’s the underlay I had down on the old laminate floor.

I think I’m gonna replace some of the badly damaged or cracked sections of floorboards.

I’ll then use expanding foam (just enough to block the gap) and then go over it with air tightness tape.

I’ll then go over the whole floor with that gold 5mm underlay tight to the walls.

Ill then tape the underlay to the walls (which will be hidden by the skirting) with air tightness tape.

I’ll then install the 12 or 14mm laminate flooring (not sure which one we are getting yet) with an expansion gap at the walls.

Skirting board will then go on top.

sirmixalot

https://www.boards.ie/discussion/comment/121858843#Comment_121858843

That sounds the job, you'll certainly notice the difference.

tom1ie

https://www.boards.ie/discussion/comment/121858693#Comment_121858693

I’ve had 5mm gold acoustic underlay under my existing laminate for about ten years with no issue.

The only reason we are pulling it up is we can’t get that laminate anymore to match into an adjoining room.

circadian

I put this stuff down last year, massive difference on a suspended timber floor;

https://www.ecologicalbuildingsystems.com/product/solitex-plus

https://www.ecologicalbuildingsystems.com/product/tescon-vana

https://www.ecologicalbuildingsystems.com/product/da

https://www.ecologicalbuildingsystems.com/product/thermo-hemp-combi-jute