Swimming Pool Blog

Spring is Pool Renovation Time!

by Rob Cox, April 20, 2010

Spring is Pool Renovation Time!

Every 20 years or sometimes sooner, all pools need to have a facelift. For one of our customers, Charlie O, In South Jersey, he has been emailing back and forth with me about sprucing up his 30 year old Sylvan pool. His pictures and our back and forth conversation seemed a good topic for a blog post. So here goes...!

Ok, “Mr. I have a bunch of experience with Sylvan pools”……. I need some advice!!!  I have some separation between the coping and tile. Worse than I imagined. The morons that reconditioned the pool for us 5 years ago should have caught this stuff!!

Question 1. What do you suggest for the margin between the tile and coping??  Silicone? Grout? Something special? Don’t I really want something with some real flex like silicone? The problem with silicone is that is mildews over time, etc. Maybe a special grout?

pool renovation pic #1


Answer 1: First I would rent a 4” grinder, with a diamond blade (a cheap one) or a thin carbide blade. Use gloves, goggles, facemask and hearing protection, and be very careful with this dangerous tool. Use the tool to carefully, slowly, enlarge and clean the groove. If you slip, or use too much downward pressure, you will cut into the tile or scrape up the tile, or pop the tiles, so be focused. Afterwards, hose the joint out clean. Mix up small batches of pool plaster, and force the mix into the groove with a spreader or putty knife. If this is hours after you first hosed it out, hose the joint again, so that the surrounding concrete does not suck out the moisture from our plaster mix. Push in enough mix so that most of the crack is filled, several inches deep. Use a wet sponge after a hour to run along the joint again, to smooth and shape and clean the tile below. After 24 hours, clean again with a wet scrubber sponge, to remove extra plaster mix that spread onto the tile and coping.

Question 2. I have some other issues here (below) that I think will require plaster and grout?  Do you agree???
pool renovation pic #2


Answer #2: You can see the plaster from the last plaster job that is between the third row of fish tile. Plaster is actually the grout that was used on many pool installations, and it still makes a nice grout today. Use the same plaster mix to spread into the areas needed. But first spend some time with a small flathead screwdriver and small hammer to chisel out any loose, stained, old material. It also may be helpful to clean the tile with a degreaser agent like TSP, or Simple Green to help the plaster bond. Just like with pool paint, an acid etch will also improve the bond of the plaster mix to the tile. Use a flexible rubber spreader, or in a pinch, break off the handle from the kitchen spatula to force the material into the cracks. Finish the job with a wet sponge in the same way outlined above.

Question 3. Ah yes, here is a small crack that was leaching water yesterday from the tile and plaster crack. I assume I should open the crack and then use some plaster patch I just purchased from you and then grout well??
pool renovation pic #3

Answer #3: Ah, you have what we call a “weeper”. Make sure this is dried up before you start painting. Using the grinder from step one, enlarge this crack – just a bit. Chip out any loose or hollow material. Fill with plaster in the same way as outlined above.


Question 4. The grout seems to be almost 100% gone everywhere. It looks like just the thin-set is left. Is this normal after 30years or so??? I think I ordered 3 5lb kits of grout from you. Is that enough?

pool renovation pic #4

Answer #4: This is normal, after 30 years, water and chemicals will degrade plaster and grout. Notice how more of the grout is missing on the lower half of the tiles, beneath the water line.

Tapping the tiles will tell you if there are hollow spots behind them. The same can be done with coping stones. If some tiles are very loose to the touch, you may wish to carefully “pop” them out with a small screwdriver. Then carefully chisel out an 1/8” of the old thinset behind the tile. “Butter” the back of the tile piece with a thinset mortar mix, and push in place. Extra material will squeeze out, just wipe it off and mostly out of the grooves with a wet sponge or rag.  But if the tiles are still held in place, the new grout job will help to hold them in place. This is necessary, and you’ve let it go too long (shakes a finger) – during the winter, water getting behind the tiles will freeze and over time, loosen your tiles.

You actually ordered 3 – 10 lb kits, so you should have more than enough. Remember to mix in small batches. Read the instructions thoroughly – and watch the EZ Patch videos on the mixing and application of these grout and plaster on our website.


Question 5. How about this area? Just re-plaster???

pool renovation pic #5

Answer #5: Skimmers (like coping stones) are subject to the movement between the pool and the deck. This crack looks to me like it probably leaks. What I would recommend is to remove the remaining tiles in the area, and save them (you may need them elsewhere). Use the grinder to enlarge and clean the diagonal crack. Hose clean and fill with plaster mix. Chip the grout out carefully next to the remaining tile. Clean with degreaser and acid mix or use the Ramuc Clean & Prep solution to ensure a good bond.

Buy a 12x12 sheet of a light blue 2x2 tile that you can live with ( I can pick something out for you). You may need a tile cutter or tile snips to cut the tile near the top. Once you have measured and cut a new strip of tile that fits the area, wet the area and the back of the tile with water. Mix up a small amount of thinset mortar, and use small notched trowel to spread the mix, no deeper than 1/8”. Press your tile sheet into the mix, pushing firmly and spreading the tile joints evenly. Keep your eye on it for 15-20 minutes, to make sure it doesn’t peel off. If it does, you may need to scrape clean and re-do it. To assist, sometimes, tile guys use duct tape to hold it up after pressing it in place. After several hours, use a wet sponge to clean the area up. After 24 hours, you should grout the area.


Question 6. I have two drains, each with a port on the side (which I assume runs to the filter). Neither drains sucks real well. The deep drain has a plug in the bottom (one of those rubber things). I assume this stays in place and is the hydrostatic relief?

The other drain has what looks like plaster in the bottom? Any idea why they would have done that?

pool renovation pic #6

Answer #6: Having two drains is a safety measure, used by Sylvan pools beginning in the late 80’s. They are connected to each other by a pipe, to prevent and entrapment injury of a single drain. The side hole of one leads to the pump, usually the one closest to the equipment. A center bottom hole would be a hydrostatic relief plug, you are correct.  This is important to remove once you drain the pool, in case there is a high water table putting pressure under the pool. If a rubber plug is used, that is OK, but these degrade and should be replaced every 5-7 years. If the hole is threaded, you can get  a longer life from using a threaded plastic plug, usually a 1.5” threaded plug.

Older Sylvan pools had the main drains connected to the skimmers, and did not have a line running all the way to the pump, with a separate valve to control the drain. The latter, with the separate valve, is a superior design. If you don’t have a dedicated valve for the main drain in front of your pump, then your drains connect to your skimmers, the pipe from the drain connecting either to the front hole in the bottom of the skimmer, or on older pools with only one center hole in the skimmer, the main drain pipe connects to the skimmer pipe underneath the skimmer, and flow is controlled by use of a diverter or a sylvan “skimmer stick” – a 12” piece of schedule 20 pvc pipe.

Plaster in the bottom is not unusual with sloppy plasterers. There looks to be another plug underneath the plaster in the picture, but don’t worry about it. If the entire main drain pot were filled with plaster or cement, then we could assume a leak in the drain line, at which point the homeowner or service company decided to abandon the line, and fill it solid.


 Question 7.


For the pool light at the deep end...It is a flat, 12" diameter assembly with two filament bulbs. As long as I am re-mortgaging my house to complete this project :-) ... is there anything cool you could sell me to stick there? LED multi-color. Strobe with disco effect? I think the last time I asked you about this light, you indicated it was kind of unique to Sylvan, maybe I''m stuck with it?

pool renovation pic #7

endif-->lamp will fit the paragon niche. I assume that you are 120V (not 12V) – so the question is how long of a cord do you need? Measure from the pool edge to the junction box, and add 4 feet. Many sylvan pools had their j-boxes behind and under the dive stand. (picture sent after response) Some older sylvans have a deck plate very close to the edge of the pool (no longer up to code).


The Hayward light will fit into your current niche (bucket) so you only need to get the proper length (30’) You can choose from stainless bezel or plastic SP0525LED30 or SP0525SLED30 – The color modes change when you flip the switch (or breaker). No remote control, sorry. To replace the light, look here These should be just as bright as your existing light. But saving on electrical use.