Laitance removal - underfloor heating screed

[kiteboy]

Hi all

Just been reading up on the above and it looks like I should have sanded the floor down a bit sooner - no one advised that it should be done after a couple of weeks

Floor has been down a good while now and has a good surface I think - its not crumby at all but hey may as well do a proper job now - I dont want these tiles popping off!

Anyway about to get a tiler to do the floor - but would like to sand it down first and been looking at the costs of the machines

Surface Texture Grinder Str701 110V | Travis Perkins - https://www.travisperkins.co.uk/Surface-Texture-Grinder-Str701-110V/p/522104

Didnt factor that cost in - wow - is this the best thing to do it - only have about 20square meters to do - could try a belt sander - no idea if that would work

Also was planning on putting Bal floor primer as advised by the builder - would you recommend staying with Bal for the adhesive or doesnt matter really

Thanks all

 

[Chris Gibbs]

I use a handheld concrete grinder, does the job in seconds ( with a vacuum attachment) a belt sander may work. I use tilemaster primer, its never let me down. oh and use a compatible adhesive for laying the tiles. Tilemaster do a product called Anhyfix especially for anhydrite floors.

 

[J Sid]

what is the screed?
how long has it been down?
has the heating been commissioned?
has the screed been tested to see if it's dry?

 

[kiteboy]

Had a dig around on my photos - went in on 27th July and it was 50mm depth - dont know exactly what screed it is - but its grey and calcium sulphate - yes underfloor heating is on and linked to thermostat

Not tested as been down 6months! - Cant believe its been that long - you can see why the missus is on my case!

 

[Flintstone]

Yes it needs sanding and you won't do that with a belt sander after 6 months you need a diamond cup on it.

 

[Tile Fix Direct]

Norcros do a fixing system for Anhydrite screeds that only requires a light sanding of the surface that does not need a machine;Norcros Pro Gyp-Base - https://www.tilefixdirect.com/product/Norcros-Pro-Gyp-Base