Screed

[Tim Streater]

We had the screed floor put in our new porch over two weeks ago now, including some fibre and rebar. Its 100mm thick over 100mm celotex.

Now, how long does this take to dry out? Our plumber, who also does general construction, reckons its 1 day per 1mm of thickness (so three months in our case), but he reckons we should be able to finish it off (vinyl) in two months.

Also: there'll be self-levelling on top of the screed (a couple of mm). I'm sure I saw a comment somewhere that it's porous and so could be put down sooner (i.e. the screed would still dry out through it). Is this the case? And what does it consist of anyway?

Ta,

[The Natural Philosopher]

times are reasonable and self levelling is adequately porous yes.

Id not vinyl it though, for a month or two.

[stuart noble]

The self smoothing screed based on SBR (aka latex) is not at all porous

[Andrew Gabriel]

I did something similar in a fireplace (but used vermiculite rather than celotex;-) It probably did take at least 3 months to dry out.

I would put something else porous on it first, such as a carpet off-cut or similar. When you think it's ready for vinyl, put a sheet of plastic down under the carpet for a day or two, and check the back doesn't get wet with condensation overnight (or when the porch gets coldest).