Tiling screeded floor

[Kate]

Just about to have a floor tiled with porcelain tiles that was screeded 45 days ago over wet u/f heating. Heating yet to be commissioned. Using correct flexible grout, is it ok to go ahead with this? Thank you.

 

[bugs183]

Hiya.
What is the screed, concrete or gypsum based product (anydrite).
What depth was the screed laid too??

 

[Kate]

Concrete mix,60mm deep. Thanks, Kate

 

[Andy Allen]

the ufh should be commissioned first...

 

[Kate]

Hi Andy, thanks. Could turning on the heating afterwards then possibly crack the tiles? Have the tiler lined up and not sure if I can get the heating guy back first. Kate

 

[Andy Allen]

the screed needs to expand and contract before tiling, if you tile first, then commission the heating it could depond or crack the tiles...

 

[nybor62]

i agree with andy, commission heating before fixing any tiles

 

[Del W]

The ufh has to be run up before any tiling is done. Has your tiler not mentioned this ?

 

[afright]

If you,re having a tiled skirting make sure you leave an expansion joint.

 

[Ajax123]

There are a number off issues here. Firstly the heating should ALWAYS be comissioned and run prior to tiling. If you don't expect a failure.

"concrete mix 60mm deep".... I ake it ou mean sand cement screed. At 60mm this is not deep enough for the application. Sand ement on insulation should be a minimum of 65mm on insulation. That means that as the bit ver the pipe is the thinnest bit and taking the pipe as 15mm diameter then the overall depth of screed from the insulation to the top of the screed should be 80mm
. The British standard suggest a design depth of minimum 75mm with this type of screed. The overall success of this depends on several factors.

1. Mix design should be minimum 4parts sand to 1part cement
2. Should be fully compacted bu I is always difficult of near impossible to get dry screed under he pipes hence the extra depth requirement
3 should be properly curd by covering with a sheet of polythene for minimum 7 days from installation.

You sound like you are trying to rush this as your tiler is busy but really you will pay dearly if you do rush.

Due to the screed depth I would also opt for an uncoupling membrane as it is likely to crack in the medium to long term.

 

[Kate]

Thanks Ajax123, will speak to my tiler who has come late to the job and I probably failed to mention that the heating was yet to be commissioned. Kate