How to Waterproof a Swimming Pool

Projex - How to Waterproof a Swimming Pool

Over time, the waterproofing structure of most pools will develop faults and failure points due to the constant internal and external forces hitting it. While often beginning small, these cracks can lead to serious leakage.

If the pool is already existing, finding the cracks alone can take a significant amount of time, and most people won’t have the technical know-how to do something about it, even when they find it. Having a plan to both identify your current situation, and the steps needed to fix it, is tantamount for not spending twice as much money on your pool a year, or ramping up a significant amount of maintenance costs.

Is my pool leaking?

The first step for fixing the waterproofing for an existing pool is to determine the extent of the issue at hand. Although waterproofing decay is a gradual process, this slow development can make it hard to detect. For this reason, you shouldn’t be checking for major faults and cracks in all but the MOST neglected of pools. Instead, keep an eye out for minor faults.

One easy indicator of a leak is in the pool’s water levels. Usually speaking, a pool should lose no more than two inches of water per week. An amount equal or greater to this is usually an indicator of either an unsound pool wall or a leak in your waterproofing solutions.

If you’d like a quicker check, you can do the same as a daily test. It’s a little less robust, but simply mark a line by either getting a waterproof marker or some form of tape that will stick and hold overnight in water, and place it securely at the exact water level.

Leave it for 24 hours, preferably while not using the pool to account for any water displacement, and then check it again; if the water level has dropped a significant amount (and in a body of water that big, anything over 1/4 of an inch is significant), then you most probably have a crack.

Another telltale sign is in upkeep costs. If you have a higher water bill than you remember (and your rates have remained unchanged, obviously), it might be time to give the above methods of checking a trial. Likewise, if you seem to be spending a lot of time and money adjusting the P.H level of your pool, it might not be the water being volatile, but simply the water level vs. chemical adjustment being out of tempo.

Where is the leak?

Simple cracks

There are many components of swimming pools, and so it can be hard to determine precisely where a leak stems from. However, the main components at risk to water seepage and leaking are those which have gaps or seals, and so a large amount of leaks can be found by tracing them back to their source: namely, this refers to the filter, heater, pump, and pipe valves.

Pay special attention when looking at these elements in particular, and check each segment of piping for leaks; this applies doubly so for joins, which may be the result of wear on seams or one part being better designed for long-term use than the other. If the part is detachable, detach it and run water through it, seeing if it drops out anywhere it’s not supposed to along the chain.

If there’s nothing obvious, you may be encountering something more serious. For example, a common issue among older concrete pools lies in their sealant; incorrect or insufficient waterproofing often allows pool water to leak through the membranous grouting of the tile line over time.

Complex cracks

If you’ve deduced that the fault is not in a join or piping, then you may be dealing with a crack in the membrane itself, or worse, the actual stone walls of the pool enclosure. If the above methods don’t work, try running about half of a small bottle of food colouring into the pool. If you don’t have any, some other form of coloured, non-toxic identifier that you wouldn’t mind potentially coming into contact with your skin in a watered down form will do.

Check on this every few hours, and identify where the water (highlighted by colour) conglomerates, and where it stops flowing. You may also see discolouration and buildup of the dye in specific sections of the pool, which is a good place to start looking for cracks. This process can take (depending on where the crack is) anywhere from a few hours to the better part of a day.

In these cases, it’s essential that you fix the issue as quickly as possible to prevent further damage and to cut down the growing economic costs of water seepage on your bills.

Preventative checking

Even if you don’t think you have a crack, you should conduct a full check bi-annually, or more frequently if your pool is more than ten years old.

You won’t have to do an entire piece-by-piece check, though we recommend doing so every year or two regardless, but at the very least spend ten minutes every couple of years affixing a tape\marker check or throwing some dye in with the water and check on it every so often.

It’s not a lot of work, but remembering to do so could save you a lot of money. Mark it down in your calendar, and take the opportunity to compare a few water bills around the same time, or check how much of your pool chemicals you’ve gone through, to check whether there’s a fault that you should be doing something about immediately.

Making your pool winter-proof

Projex - How to Waterproof a Swimming Pool (2)

As a subset of preventative checking, even a household in the highest Australian heat during summer should take some steps to prepare their pool for winter.

During winter, you’ll be using the pool less, and lower temperatures combined with disuse make for a bad climate for your water. Thankfully, a lot of the algae and other nasty growth requires heat to grow, so you’ll be a little less prone to green outbreaks. However, this doesn’t mean that you shouldn’t still be vigilant.

Here’s a short checklist to add to your process for winterising your pool. Combine your time spent doing this with a few of the tips for checking outlined above and you’ll save a day of work by bundling waiting away for the test results with the work of winterising!

  • Thoroughly clean the surrounding areas of your pool, preventing accumulation of debris that could contaminate the pool water.
  • Remove your pool cover from storage if you don’t frequently use it during summer; check it for wear and tear on both sides, and clean it thoroughly to prevent any contamination from long-term storage.
  • Turn off your pool heater and store any unnecessary or affixed components.
  • Remove, clean, and store your pool accessories to prevent damage.
  • Continue to test your pH level every so often during the winter.
  • Shock your water by using a pool shock product. Also known as ‘super chlorinating’, it hugely increases your chlorine amount for a short period of time in order to boost the existing supply and to kill things that regular doses can’t get to. During this time, you shouldn’t be using your pool.
  • Run your pump and filter for a minimum of eight hours.
  • Clean your pool thoroughly, including the surface and the floor, to remove the beginnings of any algae or contaminants that will develop over winter.
  • Clean your cleaning equipment, including your chlorinator, skimmer basket, and fillers.
  • Lower your water level significantly; somewhere between 10 and a maximum of 18 inches.
  • Drain and store your pump, remove your water hoses, and cap all openings.
  • Turn off any power, store any cords, and turn off your pool equipment circuit breaker just to be certain.
  • Retest your chemical levels after doing all of this, one final time.
  • Cover your pool with your tarp (or other pool covering), and secure it down with some kind of weight. Cable-ties and sandbags both work wonders here.
  • Continue to check up on your pool weekly. Do a thorough check every month or two – even during disuse.

Fixing a leak

Once you’ve spotted a leak, there are a variety of fixes dependant upon the source.

If you’ve determined that your leak is being caused by pool equipment (either a leak in the piping, in a join, or from simple degradation over time) then you have a comparatively simple fix. Merely replace the affected part – however unfortunately, this can often mean replacing the entire surrounding entity.

If you’re extremely lucky, the part can be something easily replaced by a layman. If the part is obscured or requires fixture, or is otherwise complex, you’ll need to call a pool repairman or other professional. Knowing precisely what’s wrong ahead of time, however, will cut down on the amount of time that they need to spend, and potentially lower your bill for a checkup.

Attempting to fix the problem yourself or by using an incorrect solution could not only be ineffective, but also hinder the capability for somebody to provide you with the correct fix later on.

Weighing up your options for fixing waterproofing issues

Option 1

Option 1 is, of course, to not do it yourself. Research or get a quote of how much it would cost to have your pool fixed by a professional, and weigh up whether the time, cost, and effort weighs for or against a DIY job. If you have a vinyl pool, you’ll often be looking at a massively inflated cost to DIY, as well as a harder job with more chance of ruining it.

Option 2

Option 2 is to purchase some rubberised pool paint, which you can coat the inside of your pool with to seal against any cracks. This is a good option when you have multiple cracks or aren’t quite sure where they are due to complications.

Combined with this, if you have a cement pool, simple hydraulic cement can be used to fill in gaps. If you’re working with a stone pool, this is much more likely to require removing and replacing the stone entirely; leave this to a professional if possible.

If you’re planning to do this, you should undertake the following steps. Check against your specific paint and take any advice it gives as law, but it should follow these general steps regardless:

  • Firstly, drain the water and make sure the pool is 100% dry. This might seem like an obvious step, but a lot of people forget to consider that an area of the size of most pools can take a long time to aerate and fully dry out. This can take between 3 days and a week.
  • Use a power washer or similar to get rid of any other paint or paint residue, as well as deep clean the pool surface.
  • If you HAVE painted before, always use the same type of paint that you used last time. Don’t switch up and use a rubber product if you’ve previously used acrylic or epoxy.
  • In a concrete pool, now is a good time to mix and apply a thin layer of hydraulic concrete over any gaps. You’ll be painting over it soon, which will remove the inevitable discolouration.
  • Use a large brush or extension roller to apply the paint at the thickness dictated by your brand and style of paint. Pay special attention to getting the area around your fixtures perfect and exactly to the line.
  • Wait the required drying time, and then add an additional 30% to make sure of any outlying areas. For best results, wait a minimum of 5 days.

Option 3 – Re-installing the waterproofing membrane

Option 3 is to re-apply the waterproofing membrane of your pool for ultimate longevity and waterproofing stability. This will provide an all-rounder solution to your pool waterproofing for many years to come.

Cosmofin and Wolfin are both environmentally conscious, German-engineered 1.5mm single-layer waterproofing membranes designed for both easy application and maximum protection. They can be applied on surfaces including concrete, timber, steel, CFC, masonry blockwork, and more, and can even be applied over existing, failing waterproofing membranes to bolster and surpass them. Wolfin and Cosmofin membranes can also be flood tested and have amazing flexibility and elongation properties, allowing the structures to move without the membranes being breached or compromised. Contact Projex today to discuss how our innovative, top-of-the-line Cosmofin and Wolfin products (installed by our accredited licensed contractors) can waterproof your pool to the ultimate standard.