Laying a concrete floor with two levels of dpc Re-generate an old or tired space and give it a fresh breath of life. Click here for answers, information and tips

[tannoy]

Hi everyone, I'm laying a 4" reinforced concrete floor on a dpc membrane.

On top of that I have read I need to put another dpc before I put 4" of floor styrene to which I'm adding water underfloor heating and then a 4" screed to finish off.

My question is how long to let the first four inches dry out before I put the next layer of dpc. I read I need this dpc to protect the polystyrene. If I cover it before it's completely dried right through will I have problems because the moisture is trapped in or will it eventually dry out. Any advise is gratefully received. Thanks

[mdpmspitfire]

i would suggest you allow several weeks to allow drying as you are right that the moisture will be trapped. using a dehumifier on a low setting would help but dont dryout too fast. air circulation is best but this time of year and damp air doesnt help
mark

[TheDoctor5]

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