Help!: Marmox Backerboards

[Threeskins]

Hi,

I'm not sure this is the right area for this post but hopefully someone can give me good advice. I have been recommended to use a Marmox type waterproof cementatious backer board to build up to the required height (20mm) of my concrete floor in the living room. My final floor surface is going to be a good quality laminate. My questions is, can I use laminate underlay and laminate directly on top of the Marmox style backer board?

Thanks

[bert&ernie]

Hi,

I'm not sure this is the right area for this post but hopefully someone can give me good advice. I have been recommended to use a Marmox type waterproof cementatious backer board to build up to the required height (20mm) of my concrete floor in the living room. My final floor surface is going to be a good quality laminate. My questions is, can I use laminate underlay and laminate directly on top of the Marmox style backer board?

Thanks

Hi Three,

Yes you can use that type of product to build up height and yes you can use the underlay and laminate directly on top of the backer boards. I would make sure that you either use a membrane with the underlay or ensure that the backer boards and sealed together with jointing tape.
Although the boards are waterproof this will stop any moisture coming through the joints and damaging the laminate.

Can i suggest you contact Uheat www.uheat.co.uk as they have some great prices on backer boards. have a look at Underfloor Heating | Floor Insulation | Uheat

[david campbell]

if it's for making up a height difference below laminate you would be cheaper using plywood as it wouldn't even need screwed to the floor,actually even cheaper again using chipboard!

[wetdec]

Bull.......Wasting your money, effort and time......Shuttering ply, Sterling board and a box of screws will do what you are asking. Vapour check as recomended by supplier.


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[Threeskins]

Thanks guys for the replies, what I didnt say was that my subfloor was previosly comprised of a hardwood tongue and groove baton stuck down with a bitumen type substance onto concrete. I then had a 9mm laminate (Quickstep) with appropriate DPM underlay on top of this. Following a radiator leak (which I though had dried and wouldnt do to much damage) the hardwood subfloor lifted and pushed everything up. Also in areas not near the leak the top of the hardwood sub floor was covered in mould. I have been told that laying laminate on top of real wood on concrete is not a good idea because if there is any moisture present all (leak or otherwise) the wood cant breath and sweats away. (there are no airbricks)

The solid wood batons were 20mm thick with laminate and underlay on top, hence the reason why I have to make up the 20mm depth. I am slightly worried about the natural humidity level hence the reason for using the cementatious backer boards and not a wood product to build the height. The only problem I have is that I have 41m squared to build and its damn expensive.

[wetdec]

Thanks guys for the replies, what I didnt say was that my subfloor was previosly comprised of a hardwood tongue and groove baton stuck down with a bitumen type substance onto concrete. I then had a 9mm laminate (Quickstep) with appropriate DPM underlay on top of this. Following a radiator leak (which I though had dried and wouldnt do to much damage) the hardwood subfloor lifted and pushed everything up. Because you created a vapour trap, hence the blowing of the hardwood floor Also in areas not near the leak the top of the hardwood sub floor was covered in mould. I have been told that laying laminate on top of real wood on concrete is not a good idea because if there is any moisture present all (leak or otherwise) the wood cant breath and sweats away. But laminate is an overboard system designed for concrete and wood floors with a vapour check in place (there are no airbricks) No airbricks required

The solid wood batons were 20mm thick with laminate and underlay on top, hence the reason why I have to make up the 20mm depth. I am slightly worried about the natural humidity level hence the reason for using the cementatious backer boards and not a wood product to build the height. Your not getting it the vapour barrier goes directly over the concrete under your ply or sterling board, this isolates the wood from the concrete, the laminate then sits floating as always over the top. The only problem I have is that I have 41m squared to build and its damn expensive.

Your 1 and only problem all along is your barrier was in the wrong place......


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[Threeskins]

Thanks Wetdec, I assume with the backerboards now making up the depth that I dont need a DPM underneath them because they are vapour resistant.

[wetdec]

No you will need it above instead......................................

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[bert&ernie]

I disagree.
I do not see why you would need a DPM sheet As long as the board joints are sealed properly.

[wetdec]

I disagree.
I do not see why you would need a DPM sheet As long as the board joints are sealed properly.

So how would you do that then and how would you fix them ??

[bert&ernie]

what the hell has fixing them got to do with it. The question was about the DPM sheet.

[Dave]

what the hell has fixing them got to do with it. The question was about the DPM sheet.

Chill out...

[wetdec]

Maybe you didnt get what I wrote :

The question was how would you do that (as you said you would seal the joints) and I added how would you fix them

Apologies if it was a little confusing...........

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