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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Carpentry Questions >> Insulation https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1257286304 Message started by sparky415 on Nov 3^rd, 2009, 10:11pm

Title: Insulation
Post by sparky415 on Nov 3^rd, 2009, 10:11pm

I've been thinking about installing laminate floor through my living room,
It has a suspended floor, chipboard with 70's insulation,
(looks like tar paper with 1'' fibreglass stuck to the underside)
As the chipboard is in good nick (replaced a few years ago)
I want to add insulation value as I lay the floor
What's best? should I use something like this?

http://www.realoakfloors.co.uk/depron_wood_flooring_insulation.php

www dot underfloorheating-mats dot co dot uk/6mm-thick-lamfoam-underlaminate-floor-insulation-128-p.asp

[edit]Link edited to non clickable type at request of site owner[/edit]

Thanks Lads [smiley=beer.gif]

Title: Re: Insulation
Post by woodsmith on Nov 4^th, 2009, 7:38am

I haven't used either, there are no details for thermal values so they may not be very effective :-/. Then again anything is better than nothing, and you will need some form of cushioning under the laminate.

Title: Re: Insulation
Post by Joiner on Nov 4^th, 2009, 8:28am

Colin will know! He'll probably get back to you when he's finished playing with the kids Scalextric. ;D

Title: Re: Insulation
Post by CWatters on Nov 4^th, 2009, 2:36pm

Several web sites claim the thermal conductivity (of a nominal 1 meter thickness remember) of Depron is around 0.035 W/mK. That would mean a 6mm thickness would have a U-Value of about 5.8 W/m^2K. To put it in context the building regs for walls and floors require more like 0.2 to 0.35 ish so 6mm Depron doesn't reall add a whole lot of insulation in real terms.

Having said that if 6mm is all you can really afford to raise the floor levels then go for it. Some insulation is better than none. It would be much better to lift the boards and put 100-150mm of something else between the joists.

I look at all insulation this way...

Aerogel is the (or one of the) worlds best and most expensive insulating materials but even only that has a thermal conductivity of around 0.013 W/mK ... So you need 60mm of Aerogel if you want a U-Value of 0.2 W/m^2K. Any other type of insulation would need to be thicker to achieve 0.2 W/m^2K. Size matters as they say.

If someone out there thinks they've found a new super thin insulation (say <25mm or even <50mm) that achieves 0.2 W/m^2 then show me a test report carried out by the BRE and I'll by shares in the company ;D

PS. Depron is great for model aircraft..

http://www.depronfoam.co.uk/html/depron_models_gallery.html

Title: Re: Insulation
Post by Joiner on Nov 4^th, 2009, 5:31pm

"PS. Depron is great for model aircraft.."

See what I mean? ;D ;D

Title: Re: Insulation
Post by sparky415 on Nov 5^th, 2009, 8:33pm

Thanks CW,
I guessed you would come through :)
I am open to suggestions but I really don't want to lift the existing floor,
It would do no harm if the finish floor level was raised by an inch or two,
I did think of laying say an inch kingspan then chipboard then laminate,
good idea or silly idea?

Title: Re: Insulation
Post by woodsmith on Nov 6^th, 2009, 8:17am

Quote:

I did think of laying say an inch kingspan then chipboard then laminate,

That's what I've done throughout the downstairs at my house and it has made a big difference.

25mm Kingspan with 22mm t&g chipboard, all the joints glued, vapour barrier between the chipboard and the insulation and 25mm battens round the perimeter, across doorways, and under any high load areas. Needs an expansion gap round the perimeter too.

Title: Re: Insulation
Post by CWatters on Nov 6^th, 2009, 2:28pm

Officially if you upgrade more than 25% of the insulation you are meant to bring it up to modern building regs standard but we won't tell.

Title: Re: Insulation
Post by sparky415 on Nov 6^th, 2009, 6:43pm

Thanks Lads,
I won't be telling anyone CW ;)

So I'm thinking of a 'kingspan' sandwich

Laminate
Some kind of underlay
Chipboard
Kingspan, and battens
Existing Chipboard
Tar paper with thin fibreglass
Joists

Woody/CW/Others
Will I need a vapour barrier as well as the underlay?
Needs an expansion gap round the perimeter ?
Is this around the new chipboard as well as the laminate?

There's no rush lads as I will be surprised if its done by Christmas ;)
Thanks again, [smiley=beer.gif]

Title: Re: Insulation
Post by Lectrician on Nov 6^th, 2009, 7:17pm

If you are going to install kingspan (I assume celotex is the equiv we see down here) and a second layer of chipboard, then time and cost wise, lifting the old floor, ditching the old board, insulating between the joists and then re-boarding is not going to be too different?

Title: Re: Insulation
Post by woodsmith on Nov 6^th, 2009, 10:39pm

sparky415 wrote on Nov 6^th, 2009, 6:43pm:

Will I need a vapour barrier as well as the underlay?
Needs an expansion gap round the perimeter ?
Is this around the new chipboard as well as the laminate?

Depends on the underlay, some act as a vapour barrier and will say so in the instructions.

Its good practice to leave an expansion gap round the chipboard.

CW I didn't know that you had to bring the insulation up to current regs if you upgrade by 25%, that's crazy, what sort of deranged mind would bring in a regulation like that [smiley=duh.gif]

Title: Re: Insulation
Post by sparky415 on Nov 8^th, 2009, 7:00pm

I'm going away to think about things for a while ::)

Title: Re: Insulation
Post by sparky415 on Nov 11^th, 2009, 7:11pm

I have a simple but cunning plan.... ;)
Was talking to a mate at work about floors etc,
He asked what would happen if you got a wall insulation company to fill
the void under the the floor with the kind of fibre glass they pump in to walls?
You would get damp floors I replied....
Then thought I would ask you lot again what you thought? :-/
Damp or a cunning plan? :D

Title: Re: Insulation
Post by londonman on Nov 11^th, 2009, 10:49pm

Damp floors. You need air currents to keep everything dry. You might like to post over in the Off-Topic section in www.ukworkshop.co.uk. There's a guy there, Mike Garnham, who is really clued up on this sort of thing.

If it was me, I'd rip up the old chipboard and put some 70mm Kingspan sandwiched and then foamed - in between the joists. You don't have any open fires in the room, I'm assuming.

Title: Re: Insulation
Post by londonman on Nov 12^th, 2009, 10:25pm

Been thinking about this a bit more. Why can't you get a circular saw and set the blade depth to a smidgeon off of the depth of the chipboard. Then run the saw down the middle of a joist. Have you got a Fein? Finish the cut with that ...or you could set the depth of the circular saw to be just past the depth of the chiboard cut it all the way through. Then you might be able to lift up whole sheets of chipboard.

Title: Re: Insulation
Post by woodsmith on Nov 13^th, 2009, 7:35am

londonman wrote on Nov 12^th, 2009, 10:25pm:

Chipboard comes up relatively easily by cutting part through as you suggest but not along the joists, thats where the nails are!

Title: Re: Insulation
Post by londonman on Nov 13^th, 2009, 12:09pm

woodsmith wrote on Nov 13^th, 2009, 7:35am:

londonman wrote on Nov 12^th, 2009, 10:25pm:

Chipboard comes up relatively easily by cutting part through as you suggest but not along the joists, thats where the nails are!

But not all over the joist surely? Mind you, if he has one of those Evolution saws then it doesn't matter about the nails. ;)

Title: Re: Insulation
Post by sparky415 on Nov 14^th, 2009, 1:43am

Kango? :D

Title: Re: Insulation
Post by woodsmith on Nov 14^th, 2009, 6:50am

sparky415 wrote on Nov 14^th, 2009, 1:43am:

Kango? :D

Kango-who?

I'll just hop off ;D

Title: Re: Insulation
Post by sparky415 on Nov 14^th, 2009, 11:31am

[gallery]sparky415/1258198209.jpg[/gallery]

;)

Title: Re: Insulation
Post by sparky415 on Nov 20^th, 2009, 11:08am

OK Guys,

I'm thinking that the whole idea is too much trouble for me to do,
Doing it properly, ripping up the living room floor and insulating between the joists will take me a long time (If you saw my woodwork you would get why) :-[
I thought I would lay insulation on top of the floor but after measuring the tops of the door frames....nope ::)
So any comments on this underlay? :-/

http://www.wickes.co.uk/Fibreboard-Underlay/invt/201508

Thanks again [smiley=beer.gif]

Title: Re: Insulation
Post by woodsmith on Nov 20^th, 2009, 5:01pm

It doesn't say that it insulates for heat, only noise, so I don't expect it would do much. If you only have space for this thickness of underlay it is probably about as good as you can get. I've used it and it is a good surface on which to lay laminate.

Title: Re: Insulation
Post by sparky415 on Nov 20^th, 2009, 6:49pm

Thanks Woody,

I was hoping for a bit of both, I think that noise might be a problem (I never noticed noise before as I had both good carpet and good underlay down)
I've been sitting here every evening listening to footsteps :(

Incidentally I've gone round the edges with expanding foam (now the skirting is gone) and I don't think there's a draft any more :)

Title: Re: Insulation
Post by woodsmith on Nov 21^st, 2009, 7:14am

That can make an enormous difference, you can have a 10mm gap under the skirting all round the room, its like leaving a door open to the outside! Sealing that gap will probably make more difference than insulating the floor.

Title: Re: Insulation
Post by CWatters on Nov 21^st, 2009, 5:03pm

A 5mm thick underlay will make next to no difference to the heat lost through the floor by conduction. However putting a layer of any sheet material down might well stop heat loss via draughts coming through gaps.

I refer to my previous reply... The best insulation in the world needs to be about 50-60mm thick to achieve the level of insulation recommened for floors in the Building regulations. So a 5mm thick fiber board would be at least 12 times worse than the regulations recommend.

Title: Re: Insulation
Post by sparky415 on Nov 22^nd, 2009, 2:11pm

Thanks CW and others for all your help

I did understand that to do the best job I should take up the existing floor but to be honest its too much hassel.... :-[
So it will be just the green stuff....I know there's not much U value there but now I'm getting worried about the noise
I'm thinking there might be a few rugs, one or two of them hanging on the walls ;)

I might start knitting one :)

Title: Re: Insulation
Post by Zambezi on Nov 22^nd, 2009, 10:47pm

I have just used some of this for my new laminate floor
http://cgi.ebay.co.uk/LAMINATE-WOOD-FLOORING-UNDERLAY-5mm-SONIC-GOLD_W0QQitemZ220410394379QQcmdZViewItemQQptZUK_Flooring?hash=item33517bb70b
It has a vapour barrier and is good for noise. It works out at £2 a square meter, which is not too bad for 5mm underlay of this type.

Title: Re: Insulation
Post by sparky415 on Nov 23^rd, 2009, 9:45am

Zam,

Thanks I will have a look,
:)

Title: Re: Insulation
Post by sparky415 on Nov 24^th, 2009, 9:35pm

Any reason not to use this lot? [smiley=crossfingers.gif]
(I have ordered a few samples)

www dot ukflooringdirect dot co dot uk/info/Showroom.html

[edit]Link edited to non clickable type at request of site owner[/edit]

Thanks [smiley=beer.gif]