Hi
Hope someone can resolve my question.

I am laying my first floor.
I have overboarded with 9mm ply onto approx 22mm long strips of chipboard. Very solid.
Screwed down every 150mm and 100mm at joints.

I have Keraflex Maxi to lay 300 x 600 porcelin tiles.
I alway intended to prime the top of the ply before laying the tiles,
however I was told when purchasing the adhesive there was no need to prime the top of the ply.

I was just about to start laying the tiles, but the question of whether I should prime or not is still a concern.

Please can someone confirm which way to go and if I have o prime what would you recommens


Steve

Hi steve..welcome...

Priming ply is not nornally needed....But on that thickness of ply the moisture in the keraflex maxi might buckle it , as the maxi is slow setting..

An S2 fast set would be better.. IMO..to thin

Hi Dave

Thanks for getting back to me so quickly.



A bit concerned in what you have said about the ply buckling.
Would primming help the situation?
If so what do you recommend.


Steve

no i think the ply to thin and the slowset will let to much moisture into the ply

You will be better of using a tile backer board rather than the ply but if you insist on ply then it should be 18mm thick and primed on the under side and the edges.

since the ply has already been layed prior to the question being asked i would suggest using the Mapegum wps before the Maxi to be sure - but if you could get the Primer S it would also be more than suitable.