Repairing Waterline Tile Grout

[jimlum]

Hi,

FYI, I found a product at Home Depot named "Underwater Mortar". It's made by Custom Products. It's suppose to be used like thinset, but supposedly can be put on the back of tiles, and taken under water to attach the tiles to the wall.

We tried this this morning to re-attache the loose tiles on the top edge of our spa area, and it seems like it worked pretty well.

Jim

[Big_D]

Sorry for the slow reply Jim. Yes you typically use some type of Thin set which is nothing more than mortar fortified with a polymer glue. This is what should actually hold the tiles in place. The reason you need the glue to be water proof as some thin set will break down in water due to the type of adhesive blend. Typically in pools they use the same material you would use to set shower or bathtub tiles. The grout should also be waterproof, and I think the HD brand is Polyblend.

You are correct the grout is brittle and has little in the way of adhesive properties, more for sealing, water proofing and aesthetics.

Glad it worked
Thanks
D

[markphin]

I too have noticed some loose tiles, they have not popped off but are a bit loose, because the grout at the coping line came off, and I gusee some water got behind the tiles. My question is, can I just re-grout for now in hopes that they won't pop off, or should i cut the loose ones out and re attach per the above reccomendations? Note these tiles are above the water line as part of a raised spa.

[judas]

If the tiles are loose, you need to remove them and reattach. Just repairing the grout won't help - even though the tiles aren't submerged, water (splashing, rain, etc) will still get behind them and there will be a cascading effect of popping tiles. Better to fix it sooner rather than later...

I just went through this a few weeks ago, I had about six tiles that loosened up near the skimmer. I ended up using a 50/50 mix of limestone and portland cement, mixed with water. I used that mixture as well to grout with - I didn't really car how it looked since I plan on retiling next season.

So far so good, the tiles are firmly attached and have been partially submerged in water since I finished the job. No cracking grout, etc.