Help, Some tiles are falling off the wall!

[Chemlagh]

Thank you. What can we do to sort this out? The adhesive instructions say when tiling onto plaster use a suitable primer.

 

[DHTiling]

It all depends on how much the plasterer polished the surface of the skim coat, this will affect the way the primer can soak in without skinning ... sometimes you have to key the plaster surface before hand...

Also just to say , the 6mm trowel is not a deep enough notch.. as for a resolution, then sand the walls , prime with 2 coats of primer at 4:1 water to primer ratio, that will be sufficient to prevent ettringite..

 

[Chemlagh]

Thank you very much for your advice, we will give that a try . We probably should have painted the walls!!!

 

[bugs183]

Did you say you combed the adhesive onto the tile? Did you comb adhesive onto the walls as well?
If you haven't combed adhesive to the walls then there is no mechanical key for the adhesive to bind to the plaster, this is why it has fallen off.
And no you shouldn't paint walls that are to be tiled, you prime according to the manufacturers instructions.