Hi,

With fixing travetine onto no more ply walls,

Do you need to prime before using cement based adhesive?

What do you all advise, slow or rapid? I prefer working with slow set for walls to have more work time.

Has anyone found that travetine can stain from water ingress by using a slow set adhesive?

Thanks in advance,

Steve

There is no need to prime cement based boards. If it was me fixing porous stone, I would use rapid set. Just mix manageable batches and make sure you have your cuts sorted before you mix.

some cement boards are so pourus that they may need a primer or it sucks the life out of the adhesive if the stone is light use a white ahesive .what i do when fixing any stone is to butter the backs of the tile 100% then if it stains its all the same i have seen stone where you can see the adhesive ribs through it hops this helps

no more ply says prime with sbr or just dampen surface with water before applying addy. the no more ply does suck moisture up really quick so you would be better to prime imo

Priming is a good idea.
If you are getting ribs showing through it is a very light colored product and should use a white thinset.
Maybe try going a bit wetter on the mix to get a full contact and then you won't have that problem.
All stone should be back buttered before applying anyways and that gets rid of the rib problem also.