Is a Liquid DPM needed on a New Build concrete subfloor?

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Hi,

I bought a new build last November, im just after a little info regarding whether to paint on a DPM or not?

When the slab was poured back in June last year, the builder put in a dpm then insulation boards, radon protector thingy me bob :), then more thick plastic sheeting, re bar/Mesh then the concrete was poured.

Ive used my BASIC damp meter and its said the floor is dry, no fancy stuff saying its under 75% relative humidity.... As ive got a working DPM I cant see the real point of painting one on, but would there be any real harm of painting one on??

I was looking at a my local builders merchant own brand one that states no primer needed.. (A rubberised, bitumen based emulsion that provides a flexible barrier to damp on walls and floors)

The only thing that makes me question whether I need it or not is one internal stud wall is sat on a strip of DPM!

Thanks in advance,

Gaz
 
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Alright mate, if the concrete was laid last June it might be dry.
Needs a proper test though really. I use a mms moisture meter, not sure if you can hire them. On use a hydro meter.
What flooring is going down.
Which local builder is it and what dpm is it Gaz
 
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do not use the paint on dpm you have found. It will have to be removed before you can lay any flooring on it.

Your floor may be dry. Only reason for a surface dpm would be if fitting a solid wood floor.
 
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do not use the paint on dpm you have found. It will have to be removed before you can lay any flooring on it.

Your floor may be dry. Only reason for a surface dpm would be if fitting a solid wood floor.

Luckily not bought the DPM yet. It's Wickes own brand one:

http://www.wickes.co.uk/invt/241217

Why wood it have to be removed if I had of painted it on and self levelled over it?

Im fitting a 18mm Solid Oak Floor.

Thanks for the help, appreciated..

Gaz
 
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Whilst I don't encourage it, solid wood oak floors are often glued to slabs, if the dpm is intact and the slab dry, no need for another.
 
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Gaz, where about are you?
Liverpool or Wirral.
I'm in wallasey so if you need a trade dpm let me know.
 
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Never float a solid.

And even if you have a working DPM under the slab, a surface DPM is also required when bonding wood floors.
 
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do not use the paint on dpm you have found. It will have to be removed before you can lay any flooring on it.

Your floor may be dry. Only reason for a surface dpm would be if fitting a solid wood floor.

Luckily not bought the DPM yet. It's Wickes own brand one:

http://www.wickes.co.uk/invt/241217

Why wood it have to be removed if I had of painted it on and self levelled over it?

Im fitting a 18mm Solid Oak Floor.

Thanks for the help, appreciated..

Gaz


Due to you needing a high NM strength compound it wont be able to go over it. Also the wood floor wood pull it up. The word "flexible" says it all.

Its more designed for where you might of taken out a wall and you are repairing a DPM maybe 6" below the surface. Not for over the top on concrete.
 
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do not use the paint on dpm you have found. It will have to be removed before you can lay any flooring on it.

Your floor may be dry. Only reason for a surface dpm would be if fitting a solid wood floor.

Luckily not bought the DPM yet. It's Wickes own brand one:

http://www.wickes.co.uk/invt/241217

Why wood it have to be removed if I had of painted it on and self levelled over it?

Im fitting a 18mm Solid Oak Floor.

Thanks for the help, appreciated..

Gaz


Due to you needing a high NM strength compound it wont be able to go over it. Also the wood floor wood pull it up. The word "flexible" says it all.

Its more designed for where you might of taken out a wall and you are repairing a DPM maybe 6" below the surface. Not for over the top on concrete.

Thanks for that understand now!
 
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do not use the paint on dpm you have found. It will have to be removed before you can lay any flooring on it.

Your floor may be dry. Only reason for a surface dpm would be if fitting a solid wood floor.

Luckily not bought the DPM yet. It's Wickes own brand one:

http://www.wickes.co.uk/invt/241217

Why wood it have to be removed if I had of painted it on and self levelled over it?

Im fitting a 18mm Solid Oak Floor.

Thanks for the help, appreciated..

Gaz


Due to you needing a high NM strength compound it wont be able to go over it. Also the wood floor wood pull it up. The word "flexible" says it all.

Its more designed for where you might of taken out a wall and you are repairing a DPM maybe 6" below the surface. Not for over the top on concrete.

Thanks for that understand now!
 
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