Cracks in your concrete swimming pool understandably can cause a lot of stress. As frightening as they may be, it doesn’t necessarily mean a big expensive repair or replacement.
Repairing Your Pool
Superficial cracks (crazing) appear more commonly towards the surface of the water, usually when the pool was finished on a day where there is a lack of moisture in the air or if it was left for a while before being filled with water. These are the most common cracks and can be repaired quite easily. Surrounding loose tiles or plaster should be removed from the crack before plastering over.
Deeper cracks are usually found in the corners or at the seams of the pool, in order of severity the following methods can be used:
- POOL PUTTY – There are three varieties of putty. Mix both the epoxy resin and hardener together in equal parts and knead together by hand with a little pool water. A chemical reaction takes place to create a substance perfect to repair cracks! An advantage to using this, is that you do not need to drain the pool; however, it may only temporarily fix the problem depending on further soil movement.
- APPLYING FRESH CAULK – Caulk is applied around your pool to stop moisture getting in behind it. When the pool expands and contracts due to changes in the weather, the caulk becomes weak and cracks may appear. After draining the pool, the crack is sand cut and a polyurethane caulk is applied. Once the crack is filled, residual caulk is removed and smoothed over.
- HIGH/LOW PRESSURE INJECTION – For more serious cracks a high or low pressure injection is used with either polyurethane or epoxy. The crack is cut with a saw, sealant ports are installed and the chosen substance is injected into the ports. Once the crack is filled, the residual is removed and smoothed out. The substance is chosen depending on the characteristics of the crack. Polyurethane is regarded as highly effective for waterproofing most cracks in concrete swimming pools; whereas, epoxy is used for larger structural damage.
- TORQUE LOCK STAPLES – For severe cracks in the wall of the pool that run all the way to the floor, a method combining the injection mentioned above and the addition of torque lock staples are required. The staples are cut and installed perpendicular to the crack with a foot between each staple. These are then epoxied in place. This method is usually only reserved for the most extreme of cracks but it is regarded as the most permanent repair to large cracks.
Why Do Concrete Swimming Pools Crack?
Pool cracks are usually caused by more than one thing. The most common factors are detailed below:
- LOCATION – Pools that have been constructed on a downward slope hillside will have problems due to ground movement.
- SOIL CONDITION – Extremely dry soil that has been subject to flooding can expand and exert a lot of pressure around the shell of the pool especially if it has been drained of water.
- CONCRETE MIX AND PLACEMENT – The mix of concrete to water ratio when it is being mixed has a lot to do with how strong the concrete will be. Too much water will weaken the mixture; whereas, if the mixture is too dry it’s hard to create the shape of the pool with. It’s a fine balance to achieve but if not can cause issues of cracking.
- POOL SHAPE – There are many shapes to choose from when building a pool; however, some shapes are stronger than others. Designs that incorporate 90 degree corners are known to be particularly weak. The installation of steps and benches are deemed to make the structure weaker too. Round or oval pools are regarded as being more structurally sound.
- CONCRETE CURING – If concrete isn’t left to cure properly after it has been laid, the plaster will dry out causing cracks. Concrete should be left to cure for a minimum of 14 days.
How Much Will Repairs Cost?
The cost to repair a crack in a concrete swimming pool varies depending on the severity of the crack and the materials that are required. For the minor repairs that you think you can do yourself e.g Plastering or Pool Putty. You can pick up the required materials online or instore at your local hardware retailer for no more than £50. It is always recommended to wear appropriate personal protective equipment when carrying out these repairs.
The primary concern of any swimming pool owner is not so much the cost of the materials but the knowledge of how to conduct these repairs and this might be when you contact a professional. With the added cost of labour, basic repairs could be as little as £100 right up to major leakage and repairs for £5000.
How long does a concrete swimming pool last?
A concrete pool lasts much longer than the average vinyl liner pool (5-10 years); however, around the 10-year mark they will need to be resurfaced which will cost in the region of about £10000 depending on the size of it. The service life for the shell, assuming there are no major failures, is 50-70 years.
How much does pool leak detection cost? A regular leak detection company will typically cost between £300-400. Do keep in mind, that swimming pools lose water due to evaporation, splash out and backwashing in your filter.