Insulation under laminate for concrete floors,

Insulation under laminate for concrete floors,

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Discussion

was8v

Original Poster:

2,003 posts

209 months

Friday 2nd October 2015
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My 80's (cavity wall, loft insulated, double glazed) house has concrete floors throughout downstairs with Karndean laid on it everywhere.

The floor is always cold, even with the heating on all day and lounge gas fire going you can feel the floor sucking the heat up. I've always lived in houses with suspended floors before and it doesn't feel like this.

My neighbour has underfloor heating and thats lovely, but we can't run to that for this house.

Whats the best insulation to put down before a new laminate is laid? (I want to keep a practical hard floor throughout).

I thought about kingspan, but then the the first step up the stairs would end up weirdly small....

Is there a 10mm product out there - what have people had good experience with?

Any negatives from doing this e.g. the slab won't ever "heat up" - but it never feels like it ever has......

was8v

Original Poster:

2,003 posts

209 months

Friday 2nd October 2015
quotequote all
Ah, seems most suppliers have a 5mm thick underlay product at the most.

With anything like kingspan I would need to lay t&g floor on top to remove risk of flex, further reducing my stairway step.

Will the 5mm stuff make a worthwhile difference?

cptsideways

13,717 posts

266 months

Friday 2nd October 2015
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we have similar, I'd be interested to know of a good fix

megaphone

11,195 posts

265 months

Friday 2nd October 2015
quotequote all
Nice warm underlay and carpet are the best fix! And take your shoes off at the front door.

However I got good results from using that green felt type board under my hallway that has laminate flooring.

bigdom

2,172 posts

159 months

Friday 2nd October 2015
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We have solid concrete floors through the bottom of our house, with engineered oak flooring on top. One half has insulation under the screed, the other hasn't. Really not sure I can notice the temperature difference between them.

We have this underneath, floor never feels cold. http://www.tradepriced.co.uk/tredaire_boardwalk_la...

Gaps under skirting edge can cause draughts, silicone sealant could help.

was8v

Original Poster:

2,003 posts

209 months

Friday 2nd October 2015
quotequote all
megaphone said:
Nice warm underlay and carpet are the best fix! And take your shoes off at the front door.
Of course! but not for us.

I'm leaning towards this type of underlay - claims to have the best insulation, although it seems to be like cheapo stuff: http://www.tradepriced.co.uk/techni-board_underlay...

Seems Pergo allow installation on polystyrene: http://www.pergo.co.uk/en-GB/why-choose-pergo-lami...

Probably get a Quick Step laminate. Skirtings will come off for a clean install.

voicey

2,471 posts

201 months

Friday 2nd October 2015
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I put 10mm XPS under my engineered wood floor although you can get it in 5mm. It's been down a couple of years now with no issues. It's enough to make the floor really warm to walk on even in the coldest of winters. I'll try and find a few pics....

V8RX7

28,680 posts

277 months

Friday 2nd October 2015
quotequote all
I've just done this for my house, I went for 20mm celotex - anything less seemed pointless, bearing in mind the current requirements are around 100mm of celotex.

I then covered it with P5 T&G floor - the bottom step has been reduced by 42mm but I've never noticed it.

Andehh

7,305 posts

220 months

Saturday 3rd October 2015
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voicey said:
I put 10mm XPS under my engineered wood floor although you can get it in 5mm. It's been down a couple of years now with no issues. It's enough to make the floor really warm to walk on even in the coldest of winters. I'll try and find a few pics....
This is the route we are going down, but at 22mm thick with UFH. You can get it in basic sheet form as well.

We are getting all of ours from "the under floor heating store" though they can pricey.

voicey

2,471 posts

201 months

Saturday 3rd October 2015
quotequote all
Andehh said:
We are getting all of ours from "the under floor heating store" though they can pricey.
Just shove "extruded styrofoam" into eBay - loads of cheap suppliers.

SIM1er

40 posts

169 months

Saturday 3rd October 2015
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When refurbishing we had a problem with the old screed lifting so resorted to putting down a 12.5mm Marmox board. I did look at a Knauf product that was about the same thickness but very expensive, and the Marmox is by no means cheap.

Pheo

3,424 posts

216 months

Saturday 3rd October 2015
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10mm of XPS here added over our 1979s council screeded concrete floors. Under tile and engineered wood. Seems to have the desired effect.

was8v

Original Poster:

2,003 posts

209 months

Monday 5th October 2015
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Hmmm maybe XPS is a better choice.

Has anyone laid laminate flooring direct to XPS without a t&g layer?

Pergo say you can if the polystyrene has a minimum compressive strength of 250 kPa.

This 10mm XPS: http://www.ambient-elec.co.uk/buy/blueboard-insula... is 30 tonnes / m2 = 294kpa



Edited by was8v on Monday 5th October 17:09


Edited by was8v on Monday 5th October 17:09