Pool Info: Pool Tile Repair
Tile patterns have come a long way from the 6" x 6" blue standard. Tiles from all over the world give us an endless palette of color, shapes and sizes. Pool tile differs from bathroom tile in that it is formulated to be frost free, or manufactured to prevent water absorption. On most inground pools, the pool tile band is six inches in height, although it occasionally is installed in 12" depths. Sometimes, they just continue it down and all the way across the pool or spa. Tile provides an attractive accent to the pool's edge while allowing for an easily cleanable surface to catch oil and dirt. Without tile, there would be a difficult to remove bathtub ring.
Tile is falling off?
This could be a result of bond failure of the "mud" that was used to set the tile in. Look behind the tile for a horizontal crack. This could be evidence of a cracked beam. "Popped" tile could be the result of not having caulking in the expansion joint between the coping and the deck, allowing water to run behind the tile and freeze. Water freezing in the expansion joint itself, or an expansion joint that is not "true" and where the pool and deck are touching, will also cause tile to fall off, and create beam damage.
If just the tile has fallen off (and not the old mud) the tile may be temporarily regrouted back in place. Do not use Pool Putty, except for a temporary repair, instead, use waterproof tile grout or thinset mortar cement. If small amounts of the wall are missing, you would want to build this back up before resetting tile, using hydraulic cement. Use rebar if the missing amount is over 2" deep.
Tile has white deposits?
Known as efflorescence, mineral salts such as calcium and magnesium may come out of the grout or from the setting mud and deposit on the front of the tile. It may also originate from the pool water. The efflorescence can be scraped off with a flathead screwdriver or putty knife, and/or "burned" off with a tile acid wash. In areas of the southwest familiar with hard water pool tile deposits, service companies offer pool tile cleaning using a bead blasting technique, similar to sand blasting. Using sequestering agents and limiting use of calcium based pool shock can reduce efflorescence deposits on pool tile.
Pool tile is cracked?
This may be caused by a cracked bond beam, or perhaps from freezing surface water pressing against the tile during expansion. Or maybe it wasn't Frost Free pool tile to begin with. Small cracks can be filled in by spreading a waterproof tile grout over the tiles, but cracks running through will become visible.
Using a small and sharp flathead screwdriver and a small hammer, chisel out the grout around the tile, and then pop-off the pieces. Clean up the surface, chipping off small pieces of grout, and use thinset mortar to set a new piece of tile. Then use tile grout to fill in the spaces around the tile.
Pool tile is dirty and dull?
Cleaning tile to remove the bathtub ring can be accomplished with a small amount of abrasive cleaner such as Comet or Bon Ami, sprinkled onto a textured sponge. You can also use a Pool Tile & Vinyl cleaner, but be careful not to use any other household cleaner. Rinse well and rub with a clean sponge. There are larger pads that will attach to an extension pole, to avoid kneeling over the pool edge. Cleaning pool tile can also be done from inside the pool.
How to acid wash pool tile
Acids are the only thing that will remove minerals and many stains from tile and tile grout. Acid strips away deposits and also a thin layer of grout, so it’s best not to make it a monthly practice, or you will soon begin to see that the pool grout has worn thin in areas, and needs to be patched, or completely redone.
After cleaning to remove oils and dirt, pool tile can be acid washed to remove mineral deposits, and to brighten the grout around and between the tiles. Start by lowering the water level to the bottom of the tile.
Pour 1 gallon of muriatic acid into a 2-3 gallon flower watering can that is half filled of water. Walk briskly around the pool, knees bent and stooped over, carefully pouring the acid mixture over the tile. For best results have a second person follow immediately behind with an acid brush on a pole, scrubbing the tiles briefly. After pouring 20-30 feet, stop and rinse off the tile and coping thoroughly.
Muriatic acid is available in many home stores. Nowadays there are safer acid alternatives, that don’t have the fumes of muriatic acid. You can also use granular pool pH decreaser, diluted into a bucket full of water. Add 2 lbs of pH Down (sodium bisulfate) or Stain Free (ascorbic acid), added to 2 gallons of water.
After acid washing pool tile, you may need to adjust the pH level in the pool. A gallon of acid will lower pH quite a bit in a 25000 gallon pool, so unless your pH is high to begin with, add 1-2 lbs of pH Up (pH increaser) for each gallon of muriatic acid used in cleaning the tile.
How to replace (the entire) pool tile:
First step is to drain the pool; it can’t be done with water in the pool. Workers will first use a 4” or 7” grinder with a diamond blade to cut a straight line at the bottom of the current pool tile, to a depth of 3/8”. This creates a ledge which is very helpful to set the new tile. Air powered chisels are then used to chip out the tile and bits of grout, and to roughen up the surface behind the tile. Care is taken around the top of the tile, to avoid chipping away too much grout, or hitting the coping stone.
The process may create some holes, or expose cracks and loose material in the tile mortar bed. Fill any holes or cracks that that are deeper than ¼” with a plaster mix, and allow to dry overnight.
Sheet tiles come in 12”x12” sizes, and are cut in half with a razor knife for a 6” tile band. The surface is sprayed with a hose or sponged to moisten. To set the tile, mix up some pool plaster or thin set mortar with a liquid bonding additive. Make a workable mix, but not runny, and mix up only as much as you can use in 20 minutes. Spread the mixture onto the tile area, with a 3/8” notched trowel to rake the mixture to a consistent depth and coverage. Spread and rake about 1-2 feet at a time, and then press the 6” x 12” mosaic sheet tile firmly in place. The adhesive grout or plaster should squeeze up between the pool tiles. A grout float is useful to apply an even pressure to press in place and push down any corners or edges that are not even. Come back to each piece every few minutes, to make sure it is still in place, and not sagging or starting to fall off. If so, use gentle and even pressure to push it back in place.
For the deep end areas you can build internal pool scaffolds, or hang the tile from up top, leaning over the pool edge. Most professional installers use scaffolding.
Allow the tile to set up overnight and after 24 hours, you can spread on a waterproof tile grout, using a foam grout float to press it hard into the spaces above, below and between the tiles. After the grout has set up for 30 minutes, you can wash it down with a very wet sponge to remove any bumps or lumps, or excess material. Allow the grout to dry overnight and then rub clean with a wet sponge. A final cleaning with a small towel will remove the haze from the tile.
Add tile to a vinyl or fiberglass pool?
Vinyl pools don't have tile normally, but it can be added with a special hanger piece that allows for installation. It’s something of a clumsy arrangement, and for this reason, tile is not commonly added to vinyl pools. There is an adhesive vinyl border that can be used on vinyl pools to add a simulated tile, or to cover up stained and faded waterline surfaces on vinyl pools.
Fiberglass pools, on the other hand, can install pool tile in 6 or 12” band around the pool water line just by using silicone adhesive. Silicone grout is used in between the tiles. With good pool chemistry, the silicone adhesive can last 15-20 years. Tile is very simple to apply on the smooth fiberglass surface.
Tile replacement prices:
Standard remove and replace charges average $25 per linear foot, plus $150 per skimmer. For the average inground pool, complete tile replacement is $2500-5000, depending on size, but perhaps more on the tile choice. In many cases, the pool coping stones are replaced at the same time, for an equivalent cost. There are a wide variety of pool tile patterns/colors to choose from.