Screed Drying Times......

[Mouldy]

I have done searches but either I'm not searching for the right thing or I'm wearing my blonde wig. Or both!

An existing customer has asked me to price tiling a new conservatory. I have yet to visit the site but the information I have to date is:-

"We estimate that there is about 8” concrete then there are insulation blocks and underfloor heating pipes and then about 4” of screed.
The area is 4.4 metres x 3.3 metres"

At the moment I am assuming that the screed is sand/cement. I have no idea if they want ceramic. porc or stone. I also have no idea at present if the heating has been commissioned.

What length of time is required before tiling? What will be required if the screed is not sand/cement?

Thanks,

Ian

 

[Chalker]

It depends if you force dry the screed after a few weeks.
Basic rule is 1mm a day. So 100 days if your guess in thickness is correct.
But will depend on other factors during that time. For example; warm weather or wet weather will increase/ decrease time. Running dehumidifiers will shorten, but wet trades, like plastering will decrease!
Long and short is. It's dry when it's dry. At that point a moisture test is a must.

 

[CJ]

Bet the builder has told customer that the "floor is OK to walk on....it's ok to tile"

Heard it so many times from customers.......and some take a hell of a lot of persuasion otherwise.

 

[Andy Allen]

You can use a green screed adhesive and tile it straight away..

 

[Dave]

I would first find out what the screed is , sand/cement or Anhydrite ? , then you can see when it is to be commissioned.

 

[Mouldy]

OK guys Ill get a bit more info and report back. To be honest a longer time suits because I cant do it until early March!

ETA what % of moisture is indication for OK to tile?

 

[Mouldy]

OK, have visited site. Screed is defo sand/cement and is showing 70% on meter. UFH guy is coming in tomorrow apparently but I'm guessing the 70% is to high to be commissioning the heating? Screed was laid at the beginning of December so has been down for around five weeks or so.

 

[Dave]

That screed can be commissioned after 21 days...

 

[Mouldy]

OK, so were well past 21 days then. What about the moisture content reading @ 70%?

 

[Dave]

OK, so were well past 21 days then. What about the moisture content reading @ 70%?

Its not too bad with those screeds but commissioning the heating will dry it as its been down a while now...

I would however recommend an anti-crack matting as those screeds can be prone to cracking in the first 6 months or so...