Gypsum screed prep - TilersForums.com

[Versatile]

Hi all
In process of tiling gypsum based screed
It's one of the newer screeds that apparently don't need sanding ect
The screed has been down a while and customer thought he was running the water through the heating system to help dry
But ther must of being an airlock or dodgy thermostat because the water hasn't been going through it at temperature
That has been resolved now and has been commissioned for a week on Monday
When can I take a genuine moisture reading ? And what should it be
When can I realistically fix
I'm using tilemaster anyfix
Thanks

 

[Ajax123]

AAAAAAARRRRGGHHHHHH!!!!!

they all need sanding. there is NOT a new type available in the UK. the company i work for makes the binder for the vast majority of them in the UK.

drying rate will vary based on flow temperature and ventillation. it could be as little s two weeks but could be a couple of months. the best answer to when is simply, when its dry enough. you can moisture test any time if using carbide bomb but if hygrometer the heating needs to be off for 48hours. if they are comissioning the heating properly and offering very good ventillation with plenty of chance for the moisture to get out of the screed it is reasonable to expect a 50mm screed to be dry within about 3 weeks (comissioning procedure and ventillation essential) see the procedure in the attached document which holds true for all gypsum screeds

http://gypsol.co.uk/media/1262/4-gypsol-underfloor-heating.pdf

 

[Versatile]

Cheers Alan
I'll be sanding and prepping as normal