Leak at vinyl junction


Bronze Supporter
Apr 19, 2017

My in-laws have a pool in France which has been losing water since last season. The leak seems to take place at the junction between the vinyl liner and the fiberglass stairs.
At the end of last season, I went and used a special silicone that can cure under water, specifically designed for pools. I applied that caulk on the whole junction between the stairs and the liner, but it was either not sufficient or it already degraded.

Image Image Image

A leak detection company came and confirmed that there was no leak in any of the pipes, skimmer and main main drain. They also are assuming that the leak is at the stairs, but have not confirmed that.

When the pool was left after closing, the level went down to right under the junction, which seems to confirm the hypothesis. (for reference, the pool lost about 5000 gallons in the course of two weeks)
I suspect that the cause of the leak is that the ground shifted a bit, as we can see cracks on the deck next to the stairs. With the staircase being a solid block, a gap formed at the junction.

Now for a solution, two contractors have seen the pool and quoted a full change of the liner. Stating that a reparation never holds in the long run. Is that really necessary? and also isn't there a risk the the problem appear again anyway? the quotations are at 2200€ for a simple vinyl liner, and around 7000€ for a fiber-resin mix sprayed to form a kind of in-place fiberglass pool. I have never heard of that system before.

Any advice on my options here? Is it worth it to try and find the remaining leak with food coloring and patch it if possible? or should we go for a full vinyl replacement?

Thanks !


In The Industry
Apr 1, 2018
Bangor Maine
It appears the liner was cut to short inside the white cover that hides the screws and gasket, I would guess this part was done before filling and stretching occurred. There are a lot of adhesives that could fill that gap but they might be a short term solution, that being said, if it was my pool I would give an under water epoxy or Anderson’s seal a try before a new liner.
  • Like
Reactions: PoolguyinCT