UFH with Gyvlon screed. preparation help

[Coop5]

Hi guys,

I am after some advice from the pros, so figured id ask here.

in my new extension I have has a wet ufh system installed under some liquid screed (gyvlon evo I believe)

Its been down for over a month now at the depth of approx 50mm.

I am now ready for tiling so have been reading up on the prep (which I didn't realise it needed)

Ive been told that I should have sanded the surface after a few days to remove some of the surface dust etc.

then I need to prime the lot before I can lay porcelain tiles.

so my questions are:

What is my best option for sanding?
Whats the best primer?
What adhesive should be used? (As cement and this type of screed don't suit each other)

And finally, how can I tell for sure that the screed is ready (moisture reading)

I am aware of the 1mm a day but I want to be sure.

I hope you can help me out. I like to know what I am on about before I get a tiler in.

Many thanks in advance

Coops

 

[Ajax123]

Have a look here.... Should tell you all you need to know....
http://gypsol.co.uk/technical/information-guides

 

[Stef]

At a depth of 50mm that will take approx 60 days to dry.
Have you commissioned your ufh yet?

 

[Dave]

As above regarding to heating.

Is this the new reddish coloured screed by gyvlon ?

 

[Coop5]

Thanks guys.

not commissioned the ufh yet.

its been down since 20th march so I am thinking of commissioning the ufh over the next few days.

its the almost white eco screed.

 

[Coop5]

ok well today I have cleaned the room ready for sanding.

Whilst inspecting the floor I noticed several areas where there appeared to be something in the screed.

I took a scraper to the area and smoothed it off. The photos show before and after.

does anyone know what this is.

Thanks

 

[Ajax123]

Ooh ooh.... pick me pick me.... I know I know....PLeeeeeeaaseee??

 

[Coop5]

Please Ajax

 

[Ajax123]

Boo yah!! It's lignite. It's a contaminant in the sand. It is often found in coal bearing ground or close to it. It is not deleterious so unless it is major contamination it's nothing for you to worry about. It is quite soft so may smear or smudge when you sand the screed surface but as long as the usual precautions a re taken I.e dry it, heat it, sand it, vac it, prime it before you tile it should not be a problem. A heavy contamination would be fairly obvious as it would look like a Tarmac path. In this case rather than sanding you would be best to shotblast with an enclosed shot blasting machine.

 

[Coop5]

Excellent,

Thanks alot mate.

there isn't much so I will see how I get on with sanding.

Cheers again