My swimming pool is leaking, what should I do?

When you realise that your swimming pool is leaking, what should you do to find the problem? This is a very short article, as we could write thousands of words about each type of leak from over 20 years experience with problem pools. Here we touch on the most common problems and explain why it is more cost effective to call in a professional than try to find the problem yourself.

Leak detection in swimming pools is a process of elimination. Possible sources of leaks are eliminated until there is only one possible problem left.

There are a few observations that the client can make to assist in the detection. The first is to note if the pool looses more water with the pump running or not. If the pool looses more with the pump running, it means that the leak is in the pressurised side of the system, either the return jets line, or a fault with the 6 way valve, allowing water to go down the drain.

If the water loss in the pool is the same with the pump running or not, then the leak is either in a suction line (skimmer, hoover or drain) or it is in the structure of the pool.

At this point it is best to call in a swimming pool leak detection specialist who can pressure test plumbing lines. This is a fundamental first step. If a plumbing line has been identified as having a leak, then there are several methods of narrowing down the source, such as noise correlation, helium gas sniffing and cameras. Non of these are 100% accurate, so sometimes it is more cost effective to allow for installing a new pipe.

If pressure tests are performed and there are no leaking plumbing lines, then the next step is to start to look for problems in the structure of the pool. The swimming pool structure can leak through cracks in the structure caused by poor build or ground movement. For the trained eye, identifying a crack is quite simple. Fixing cracks is very hit and miss, if the structure is so poor that it has cracked, there is insufficient strength to staple it. We have clients that have repaired cracks every year and eventually giving up, wishing they had contacted us in the first place. For this reason, Renolit AlkorPlan liners are the best, guaranteed not to leak. The problem is fixed permanently, with no ongoing cost.

The second type of structural leak is almost impossible to identify. The structure can become porous, leaking from several different places. This is normally caused by poor construction. We have seen swimming pools built from just concrete blocks, with no infill and no steel reinforcing, so the whole structure leaks. In other cases, the concrete wasn’t poured and vibrated properly and has air pockets, the water seeps into these weaker areas and eventually starts to seep out of the pool, these leaks become bigger as the water erodes the area (much like the way a natural cave is formed). Once the water finds a weakness, it starts to gets worse and worse with no apparent source from inside the pool.

Swimming pool grout and tiles ARE NOT WATERPROOF. The grout and tiles are just the cosmetic finish. Re-grouting a pool will not stop it leaking.

Pressure testing is the first and most fundamental step in leak detection. It is critical that this is done before carrying out other works. The main reason for writing this short article is because of an enquiry received from a client with a leaking pool. The client asked us to install one of our fantastic liners as her swimming pool was leaking, but she was worried that we would have to break the newly installed pool surround (we don’t need to), but this triggered warnings for us, so after asking more questions, we discovered that the client was about to put stamped concrete around the pool as well. All of this work being done, not knowing where the pool was leaking and without having done a basic pressure test on the pool pipes, this is horrifying as it could lead to huge expense. She assumed “that the pool structure leaked because it leaked if the pump was on or not”, but had never had a profesional look at the problem. Against our advice, she had the stamped concrete installed and guess what?? The skimmer line was leaking and the brand new pool surround and stamped concrete had to be broken up to repair it.