floor tiling soon after screeding.........

[aflemi]

Friend is building his own house, concrete floors, yet to have wet ufh and 50mm screed.
To avoid waiting the 'day per mm' to lay floor tiles, is it simply a matter of a de-coupling membrane?
Also, the ufh will be incorporated in the c/h circuit so impossible to control the temp as you would with a heating mat. What can be done to prevent the adhesive failing.

 

[DHTiling]

They need to commission the inscreed heating before tiling..

 

[aflemi]

sorry Dave, you'll have to expand for me? Is there a time formula?

 

[Gazzer]

sorry Dave, you'll have to expand for me? Is there a time formula?

It means the heating system needs to be brought up to working/max temp and then down before any tiling takes place.

 

[Ajax123]

The under floor heating MUST MUST MUST be comissioned and run before tiling. This is irrelevent to drying although has the effect of drying the screed. What type of screed are you using? I assume when you say it is connected into the central heating system you are using a return temeprature limting valve. This would allow you at least some control over the temperature. As you have limited control I would recomend uncoupling anyway. But you must run the heating through the screed before you install any type of floor primer or covering.

 

[DHTiling]

Off the top of my head it is around 20 odd days before turning on the UFH..( Alan above will state the correct length of time) this allows the screed to shrink and curl , then you can use a vapour equalisation membrane to allow the floor to continue drying..and this will help with eliminating any stress on the tiled finish.

If no heating was being used then you can tile on it a lot quicker with the same membrane.. dural Ci is one i use..

 

[aflemi]

ok so the screed manufacturer will advise on time before turning on heating and commissioning strategy. Then when it has been fully commissioned, I lay a vapour equalisation membrane (dural CI?) and tile. Bearing in mind the limited temp control, we do as much as possible to gradually increase the temp to max and reduce back down as you would with a mat?
As background, the house is extremely well insulated, he is using various state of the art heat exchangers, thermal and solar heat sources etc, and reckons the house will require very little actual heating so the max temp will not be that high. Have I got it right?

 

[Ajax123]

the only thing you havenet confirmed is the screed type. Bear in mind the required depths to meet british standards etc for warranty purposes. Other than that your last post is pretty much it.

 

[aflemi]

the only thing you havenet confirmed is the screed type. Bear in mind the required depths to meet british standards etc for warranty purposes. Other than that your last post is pretty much it.

Thanks Ajax, I don't know the screed type, but will find out and would appreciate your expert input. Cheers.

 

[aflemi]

the only thing you havenet confirmed is the screed type. Bear in mind the required depths to meet british standards etc for warranty purposes. Other than that your last post is pretty much it.

Now he has decided on heating mats. Screed is anhydrite 40mm apparently ready to tile on in 3 days? Is that right and would the heating mat above make a difference? Apart from priming the screed would you have any other prep before laying the mat?