Exterior tiles on elevated spa are falling off, mortar's gone

[aasarava]

Ok, experts, what do you make of this?

I have an elevated spa with a waterfall that goes into the pool. The exterior tiles on the spa are falling off on one side, and the mortar seems to have leached out to the point where you can hear a hollow sound if you tap on the tiles. The mortar underneath the popped tiles is dry, by the way.
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet

On the other side, many tiles are cracked and chipped -- and the mortar also seems to be failing there (though without the hollow sound).
Imgur: The most awesome images on the Internet

Is this a project where I can lower the water a bit, rip off the tiles, and get to work mortaring on new ones? (Any DIY tips?) Or is there something else going on here?


Thanks!

 

[JoyfulNoise]

The damage to those tiles looks like someone was trying to chip off the efflorescence and went a little bit to hard and cracked the tiling. That's not normal "wear & tear". One the other side, it looks like the two missing tiles were installed with a thick layer of tile glue to try to make up for a difference in height (thickness) of the gunite there in order to achieve a planar surface. The problem with tile glue is it's not meant to be built up in that way and will fail very easily when it is applied thick like that.

Was this spa surface retiled at some point? Or is that the original work?

Either way, the only method for re-tiling is to chip out all that old glue, make sure the gunite surface underneath is sound and then reset the tile with new glue and mortar. The hollow sound could be a pipe very close to gunite surface.

 

[aasarava]

Unfortunately I don't know the history of the tile, as the spa and pool were there when we moved it. That exterior tile appears to be the same as what's on the interior of the spa and the pool. Those interior tiles are all in great shape.

By "hollow sound" I mean that you can tap on all the exterior spa tiles around the pieces that fell off and it's obvious that all the mortar behind has washed away and the grout is the only thing holding it all together. The whole set of tiles right there will likely come off in one sheet if I give it a yank.

I'm not sure what caused the damage to the tiles on the other plane. The damage and the white deposits were there when we moved in. I tried muriatic acid in varying concentrations, which did nothing. Attempting to scrub it off caused more of the tile glazing to flake off, so I haven't done anything else.

Regardless, I think you're right that all the tile has to come out and be put back on properly. I'm curious if anyone has tried it themselves, in particular without draining the pool too much, and can share tips?