HELP Outdoor water feature slate tile problem

[nelly123]

Pic attached.

I have built a water feature from concrete block and skim rendered them to seal. I used swimming pool tile adhesive to fix the slate tiles (8" by 18"). Some have water running over them slightly but the rest are on the outside of the feature. My problem is that the slate tiles keep falling away. I have tried to score the slates with a dremel drill to help them stick but they still fall away after a while. I have used black grout may be this would be better if I use black silicone to allow expansion. Can anyone recommend a way of doing this without the tiles falling away after a few months. I really like the feature and think that the tiles make it look good so really don't want to use anything else. The tile adhesive is not sticking to the tile, but is sticking to wall. Would painting the tile with something like pva allowing to dry and then fix work???? Any help welcome. Is there a way of fixing tiles on a runner or grip that fixes to the wall???? SOS.......

 

[Brian the Tile]

very nice water feature indeed , how long did you leave the rendering before you fixed the slate? was the rendering bone dry ? im taking it that there was no frost about ,if you have any water getting under the slate with this crazy weather that we havethe water will freeze and blow the slate off,it only takes a tiny pin prick of a hole for the water to get in ,i think if i was you i would empty the water let it dry out and check thoughlery over all joints

 

[Tony73]

Hi, very looks nice. It is important to back butter tiles with adhesive. don't paint tile with PVA.

 

[nelly123]

The render was bone dry and adhesive has stuck well to wall but not slate. The slate was sealed on the outside with water proof sealant. If anything I would say the hot weather affects it more than cold weather. When the slate fell of I could see that the adhesive had not totally pressed against the tile maybe 70 to 80% of the tile surface if this makes sense. I am considering starting again so any tips on how you would do this would be great. Thanks for the reply Brian.

 

[Dontiler]

hello and welcome
make sure you back butter the tile, don't know which ady you used but try 2 part, it will give more strength and extra flexibility, try something like ardex x7 with E 90 admix
good luck

 

[kilty55]

how dry/wet are you making the mix?

what adhesive are you using ta

 

[nelly123]

I think I will use ardex x7 with E 90 admix ( thanks dontiler) sounds like what I should have used in the first place. I will try to make my mix to a toothpaste like consistency but am open to advice. Also do I have to take off all old adhesive or can I just chip it back to allow for new adhesive layer? and is there a certain type of grout I should use?

Thanks for the replys so far.