Adhesive for Black slate patio tiles

[dave_1]

Looking for advice on which Adhesive for Black slate tiles 15-20mm thick 400 x 600 mm slate tiles to lay on a concrete base back has been down a year
Been told mapei p4 ? any advice welcome or other makes etc

 

[Steve6690]

Ardex X325 PTB would be a good choice. Or the Tilemaster PTB. I've just done 25m of those exact same tiles and used grey Ultra Trade S1 Rapid set which was fine too.

 

[Perfect Tiling]

I'd also recommend you use a pourable thickbed adhesive (PTB) seeing that you have tiles of varying thickness (uncallibrated). This will allow the tiles to be set level with varying depths of adhesive.....whichever make you can get your hands on at this time. I'd also use a primer of the same make..this will eliminate any dusty areas and also stop the sub base from drawing out the water from the adhesive too fast as it will be like a sponge being down for a year. If the base has any cracks you might want to put down a decoupling membrane as cracks in the concrete will eventually come through the tiles.