Sand and cement ratio

[ladwey]

I need to put some wedi boards on the wall for tiling. When the old tiles came off they left a recess behind them -- there's old plaster, then two feet of bare concrete blocks that the tiles were stuck to, then old plaster again below where they were. The gap's a centimeter or two, larger in places where a chunk of the concrete block came out on the back of the tiles. I need to get it nice and flat for the wedi boards to go on and be supported behind. I've got sand and cement, what's the best mix to make? Cheers

 

[Wayners]

I put a splash of PVA in water then 4.5 to 1 mix or there abouts.
The splash of PVA makes it creamy and nice to work with.

 

[ladwey]

Love it, thanks mate

 

[ladwey]

Just saw someone on another forum suggest dot and dabbing tile adhesive to the back in the void sections and then drilling through with mechanical fixings when dry. I'll be using tile adhesive on the boards anyway to fix them to the walls, so that would cut out a step and so be a lot faster, is that doable?

 

[foxhole]

Just saw someone on another forum suggest dot and dabbing tile adhesive to the back in the void sections and then drilling through with mechanical fixings when dry. I'll be using tile adhesive on the boards anyway to fix them to the walls, so that would cut out a step and so be a lot faster, is that doable?

Yes.