How Do You Repair a Crack in a Concrete Swimming Pool?

When you notice visible cracks in your concrete swimming pool, you need to take appropriate measures to ensure that those cracks don’t spoil your swimming season.  While you may feel a little stressed out to discover these cracks, the good news is that cracks don’t necessarily mean you’re up for an expensive repair.

In this article, you will discover the different ways to repair a crack in your concrete pool, depending on the severity of the problem and the type of pool crack you’re dealing with.

Some of the most common techniques pool professionals use to fix concrete pool cracks include applying putty, plastering, stapling, and injecting the epoxy.

Keep reading to learn more about repairing cracks in your concrete swimming pool.

Types of concrete pool cracks

If you’re planning to repair your pool cracks, it’s important that you know the different types of pool cracks. This is because how you treat the cracks will largely depend on the type of crack you are dealing with. Not all pool cracks mean your pool will leak, so be informed and save yourself from spending more than you need on repairs!

·         Surface cracks

Surface cracks are shallow cracks that usually form as part of the hardening process of a freshly poured concrete pool. While these cracks don’t usually cause leaks, you need to observe how they develop over time. Some surface cracks tend to become difficult to deal with in the future as they affect the overall aesthetics of your pool.

Surface cracks are usually very easy to resolve. You may observe them in the plaster of your pool and you may think of them as maintenance or repair issues, but they’re not always like that. As a pool owner, it is best not to jump to the conclusion that surface cracks always run through the shell of your pool, causing leaks. Most of the time, they don’t.

·         Structural cracks

Compared with surface cracks, structural cracks deserve more of your attention. This is because unlike surface cracks that don’t usually lead to pool leaks, there is a huge chance that your pool will end up leaking with structural cracks.

Structural cracks usually form in the pool shell and can appear in different critical locations. These cracks can either be horizontal or vertical and may emerge either on the sides or the bottom of your pool.

Most structural cracks that run through the concrete are seen through the plaster coating of your pool or the tile area over your bond beam. If you notice that your pool is significantly out of level and has some cracking, that’s a sign that your pool has potential structural cracking and leaks.

Why concrete pools crack

Pool cracks are not always results of extreme weather conditions. Below are the most common factors that lead to pool cracks:

·         Location- If your pool has been constructed on a downward slope, expect cracks to emerge often due to regular ground movements.

·         Soil condition- Pools surrounded by extremely dry soil and are subject to flooding tend to expand, exerting a lot of pressure around the pool shell and causing cracks to appear.

·         Concrete mix and placement- Usually, the strength of the concrete used to construct the pool depends on the concrete-to-water ratio when they’re mixed. If the mixture used to construct the pool had too much water, then it would turn out weak. Cracks are likely to appear when there’s no fine balance between the concrete and the water component of your pool.

·         Shape of the pool- Certain pool shapes are stronger than the others. Usually, designs that incorporate 90-degree corners are weaker than those that don’t. Pools that have steps and benches installed are also weaker and more prone to cracks compared with round or oval pools.

·         Concrete curing- If the concrete wasn’t left to cure properly—which is about 14 days—after it’s been laid, the plaster will dry out and lead to cracks.

Repairing concrete pool cracks

There are many different ways to fix cracks in your concrete swimming pool. Most pool professionals find high-pressure or low-pressure injection as the most effective way to seal concrete cracks, but there are several other ways to fix them, depending on their severity.

Most of the time, pool cracks result from uneven water pressure distribution, poor construction of the pool, and earth movement. When left unfixed, some cracks extend and become far more expensive to fix.

Here are some of the techniques commonly used to repair pool cracks in concrete pools:

·         Applying putty

If you are simply dealing with a surface crack, all you need is a screwdriver and some putty to fix it. When applying putty, scrape the full length of the crack first in order to remove the debris while widening the crack.

After scraping the crack, gently squeeze the putty into the crack until it covers it entirely. After applying the putty, this will blend into your pool, forming a seamless surface with the surrounding surface.

·         Plastering

When your pool crack is somewhere between a minor structural crack and a major surface crack, the best technique to use to fix it is plastering. This technique involves draining the pool first and then removing the hydrostatic relief plugs in the floor of your pool.

Plastering is a bit more complex than putty application. After removing the hydrostatic relief plugs, you will need a grinder to widen the crack and make a reverse V shape or dovetail. You then place a bonding additive into the crack before you use a pool plaster to finish the repair.

If you notice that the crack is more than an inch deep, however, plastering won’t be enough. In cases like this, pool professionals use hydraulic cement to fill up most of the crack before plastering.

·         Stapling

If the crack in your concrete pool runs across your pool floor and down to your walls, the best technique to use is stapling. This method allows you to make horizontal cuts perpendicular to the crack. You then drill holes on either side of the crack and fix carbon fiber or steel staples on the crack, forming a Frankenstein-like stitch to repair the crack. The last step in stapling involves plastering or painting the crack to match the repaired section to the area surrounding it.

·         Injecting epoxy

If you need to repair cracks that run to your pool shell, this technique is the way to go. This method involves injecting an epoxy sealant into the cracks under pressure and filling all the voids from the front to the back.

There are cases when epoxy injection can be used in combination with stapling to boost its bond. Although this process takes more time since it involves having to install injection ports along the crack and sealing it in place, it is one of the best methods to use if you are dealing with bigger cracks. This process takes time because you need to completely fill all of your pool cracks with the sealant.

For more serious cracks, you also have the option of using a high or low-pressure injection of polyurethane. In this method, you cut the crack with a saw and install sealant ports so you can inject the substance into these ports.

Once the crack has been filled, you can remove the residual to smooth out the crack. The substance to use in this method largely depends on the characteristics of the crack. While epoxy is used for large structural damage, polyurethane is used to waterproof cracks in concrete swimming pools.

·         Applying fresh caulk 

If you notice that your pool is expanding and contracting due to weather changes, then it is best to apply fresh caulk around your pool to stop the moisture from getting in behind it. If there have been extreme weather changes in your area lately, then your pool keeps expanding and contracting because the caulk has already become weak, causing cracks to appear.

To remedy this situation, drain your pool and sand-cut the crack before applying polyurethane caulk. Fill the crack and remove the residual caulk before smoothing the crack over.

If you are not sure which technique to use to fix your pool cracks, hire a pool professional that can expertly conduct a pre-inspection and determine the right method to treat your pool cracks. At Nelson Pool Company, our specialists prevent pool cracks from posing serious problems to your concrete pool.

Need help with repairing cracks in your concrete pool? Call us, Nelson Pool Company, at 941-256-4079 today and we will help you throughout the entire repair process.

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