Hybrid Pool Walls Question

[wpparrish]

Trouble Free Pools,

We decided to delay any major reno or building a new pool for a few years if possible so we could save up. The pool was losing what we though was a little bit of water so instead we decided to just get it cleaned up go for another year with it. When the pool guy came and we took the cover off it was nearly empty. He said not to be worried he had maintained many similar type pools and there was almost certainly a crack in our hydrostatic valve. Easy replacement and then all we have to do is keep it maintained. I came home from a business trip to see the pool had been cleaned and our hose was on filling up the pool. Since I never heard from him I called to verify that he was correct. He replied that good news the vale was fine. When I asked where 30,000 gallons of water had gone he cooly replied that they saw some dirt embedded in the line where the concrete and fiberglass walls come together and that it was just leaking through there. his replay was basically not to worry about it we'd just refill it as it lost water.Call me crazy but I think it's insane to allow 30,000+ gallons to slowly seep out under your deck and foundation.

I shut off the hose myself and the water line is currently below the line where the two connect. Is there a specific material, caulk, sealant,etc...I can apply to this join and possibly between the fiberglass joints to be safe that could get us 1-2 more years out of this pool? Dropping nearly $100k on a new pool isn't in the card right now!

 

[Bama Rambler]

A good polyurethane caulk should seal the seams fine. Since the water level is below the joint, you're at the perfect point to seal the joints.

A particular name brand is Vulkem 116, but any good waterproof urethane caulking should work. Prep and cure time is very important to the success of the sealant.

 

[wpparrish]

So I turned off the hose before the water level hit the height where the concrete and fiberglass come together. The pool has lost about an inch in 5 days (we've had 3 inches of rain as well). So it looks like the pool guy is 0-2 on diagnosing the source of the leak. I called him back and explained why the leak isn't in the wall/floor connection and he now says it must be in the plumbing or main drain and that it also must be below the water line...which means under the pool. He says fixing the plumbing could be very expensive since we'll need to tear out concrete. He recommends plugging the main drain.

Based on the threads I see here it looks like plugging the Main Drain is OK. My concerns is our pool is very deep 10-12 feet in the deep end. It seems like this area would get pretty nasty as I can't imagine the skimmers would circulate water this deep in the pool. Any insights you guys can add?

 

[blakeusa]

Before you plug the main drain I would drain the pool and check for cracks, pressure test the drain line and visually inspect the connection of the main drain to the fiberglass.

Otherwise I would get to the real cause of the leak - and fix it.

Not sure on the fiberglass pools but there could be a seal where the drain connects or maybe the hydro valve. No way to know for sure unless you inspect and test it.

 

[swimcmp]

The plastic main drain bucket has concrete poured around it at the time the floor is poured. Drain the pool, have the line pressure tested. Most likely that is the problem

 

[wpparrish]

So would any fix of the plumbing line require concrete somewhere be torn out and replaced? There is only about 4 feet of water in the pool right now which only covers a small portion of the deep end. If the leak is below the water level then it has to be covered by the pool or deck, right?

 

[ntobik]

Agreed with others. Have your lines pressure tested first before doing anything else. I've heard of some companies using sonar to find leaks too. Either method works if they can find leaks underground.

We have a 9ft deep end with a plugged main drain. Pool is concrete with a vinyl liner. I was quoted at $2-3k to redo the main drain plumbing. They'd have to cut out the side of the pool to run a new pipe.

I maintain the pool with TFP methods and it's crystal clear to the bottom. I typically vacuum once or twice a week. This gets the deep water circulating. If you have kids jumping in they'll do a great job of stirring up the water too. Vacuuming is necessary to get dirt off the bottom. I haven't felt like I need a main drain.

 

[swimcmp]

No it does not require concrete to be cut. There are products out there that can be installed into broken pipes and repair them without tearing up anything. We had a customer that looked into it and it was a cost of about $1000 a foot. But no sod or concrete was torn up. In the end he just capped the line off and forgot it.