Hemihydrate screed priming and decoupling

[dmcginty]

Hi All,

I'm a self builder and as always I'm trying to seperate the wheat from the chaff. I have been given a price for 50mm hemihydrate screed which is to be laid on 175mm xtratherm.

Originally our engineer specified 150mm insulation with a traditional 75mm screed. We are using UFH. I would like to speed up the build process as we are behind schedule, big surprise!

If i go with the hemihydrate screed can i speed up the process by using a decoupling layer like durabase ci or do i still need to wait on the UFH to be commisioned and the full 60days for it to be dry. Also how much space does this layer add to the overall floor construction. We intend to put 20mm marble on this floor and in other rooms 20mm engineered oak.

My supplier has stated that i do not need a decoupling layer just to prime with an acyrlic primer and use flexible adhesive?

When using a decoupling layer do i still need to prime the floor with an acrylic primer and what type of addy should i use to stick the decoupling layer. On top of the decoupling layer is there a special type of addy i should use?

New to all this so every bit of info is appreciated.

Thanks

[Dave]

HI and welcome..

The floor does need commissioning before tiling commences.. this can be done after 7 days.. to speed the process up you can force dry the screed by using the ufh to heat the screed and force moisture out..

We can give more info on this if required..


How big a floor area is it.?