Rebar Rust Stain Behind Waterline Tile

Here is a rebar rust stain coming from behind the waterline tile. The pool builder had repaired this several times before, or so they thought. This particular pool builder doesn’t provide me with many details of previous work, type of pool finish or even where in the pool the problem is located on their work orders although I have been asking them since 1995 to do so. In this case I knew it was a pebble finished pool and the color was Irish Mist but I didn’t know the rebar was located behind the waterline tile. I would have secured some replacement tile beforehand had I known. I expect to, as I almost always do, drain pebble pools to repair them. I brought a pump to drain it and planned to come back the next day for the repair.

When I got to the job site I thought I might be able to repair this either underwater or during a partial drain, so I started the pump and began work. Almost half of rebars behind tile don’t involve the tile at all, meaning I can do the repair without damage to the tile, I guess its easier for the rust to escape from the softer grout than the harder pebble material.

Cutting along the bottom of the tile I could see this was gonna be a tile removal job, so I cut out each grout line on one of the tile, I do this so I won’t break the adjacent tiles, and tried to remove without breaking, no luck there as the tile had been so damaged by the corroded rebar that it practically fell apart. So much for a 2 hour job. I dug out and cut out the rebars behind the tile and patched with a sub-patch so I could come back the next day and add the one piece of tile that had broken. I managed to find the last two pieces of this tile in town, the tile manufacturer for this tile is out of business now, and drove back out to the job to complete the repair. I broke one of the two tile I located for the job trying to mount it flush. Now I’m starting to worry that if I break the last piece I’m gonna be in trouble, but fear not, I managed to set it and grout it in one step.

If the original tile hadn’t broken I could have used it to complete the repair. It would have matched the other tile in terms of hard water scaling and not taken two trips to complete. I only ended up draining about 6 inches of water from this pool. I had to re-pebble a small notch under the tile and remove some residual rust from the tile and pebble. The grout will match and the hard water scaling will come in time.