The Top 5 Reasons Why Pools Develop Surface Cracks
Beneath every pool lies the ground on which it stands—an unpredictable player in the longevity of pool surfaces. The dance between the soil and the constructed basin can often lead to dramatic, unwanted shifts and cracks.
From expansive clays that swell with moisture to poor compaction, the ground's hidden movements shape the fate of the structures resting upon it.
This article plunges into the top five culprits behind the menacing surface cracks.
Reason 1: Expansive Soils and Soil Issues
Expansive soils pose a significant threat to the integrity of swimming pool surfaces. These soils, also known as shrink-swell soils, can expand or contract in response to changes in moisture content. This movement applies pressure to the pool structure and can result in cracking of the pool walls and floor. Additionally, soil issues such as erosion or incorrect compaction during construction can lead to ground movement that undermines the support of the pool, causing structural cracking. Understanding the impact of these factors is crucial for determining the appropriate measures to address and prevent undue stress on the pool surface.
Reason 2: Hydrostatic Pressure
Hydrostatic pressure refers to the force exerted by water at rest, and it can have a profound effect on in-ground swimming pools. When the ground around the pool becomes saturated from heavy rains or flooding, the water table can rise, and this increased hydrostatic pressure pushes against the pool structure. If a pool isn't properly designed to withstand these forces, or if the drainage systems fail to relieve hydrostatic pressure, it can lead to cracks in the pool's surface.
Addressing hydrostatic pressure issues can involve measures like installing or checking the function of hydrostatic relief valves in the pool. These valves help to release the pressure from groundwater, preventing it from building up underneath the pool.
Reason 3: Shrinkage Cracks
Concrete is well-known for its strength and durability, making it a common choice for swimming pool construction. However, it is not immune to certain issues, and shrinkage cracks are among the most common problems that can affect pool surfaces. These cracks are typically hairline in nature and are a natural occurrence in the curing process of concrete surfaces, including the plaster coating of pools.
Shrinkage cracks in pool surfaces emerge due to the loss of moisture from the plaster or concrete as it cures and hardens. This curing process is essential for the material to achieve its intended strength, but as water evaporates, the volume of the concrete reduces, sometimes resulting in cracks.
Several factors can influence the development and severity of shrinkage cracks:
The water-to-cement ratio: An improper mix can lead to excess shrinkage.
Rapid drying: High temperatures or windy conditions can cause the surface to lose moisture too quickly.
Inadequate curing practices: Failing to maintain the necessary moisture for concrete to cure properly can increase the likelihood of cracking.
Composition of the mix: The aggregates and additives used in the concrete mix can also affect shrinkage.
Timing of finishing operations: Working the surface too soon or too late can create surface weakness and promote cracking.
For pool owners, it's crucial to understand that while hairline shrinkage cracks might be unsightly, they do not always indicate a serious problem. They are often superficial and do not compromise the structural integrity of the pool. However, if the shrinkage cracks widen or start leaking, it is advisable to consult with a professional to determine the best course of action, which could include simple repairs like sealing the cracks with pool putty or a more extensive re-plastering of the pool.
Regular inspection can prevent shrinkage cracks from becoming a bigger issue, ensuring the longevity of the pool surface.
Reason 4: Structural Cracking
Structural cracks in swimming pools go beyond the cosmetic issues of surface cracking and can pose significant threats to the integrity of the pool. Unlike hairline or shrinkage cracks, structural cracks are often larger and deeper, indicating problems with the pool's foundation or construction. These cracks may manifest due to a variety of reasons such as ground movement, poor compaction of soils, or faulty construction practices.
If structural cracks are detected, it is imperative to consult with a structural engineer or a pool repair specialist. They can assess the severity of the cracks and propose solutions, which might range from injecting sealants to significant reconstruction work. Ignoring such cracks can lead to worse issues, including the necessity for a complete pool replacement. Regular monitoring and maintenance can minimize the risks associated with structural cracking and help to extend the lifespan of your swimming pool.
Reason 5: Improper Curing Process and Pool Maintenance
One often overlooked cause of surface cracking in swimming pools is the improper curing process of the pool's concrete and plaster. This step is critical, as it determines the longevity and durability of the pool surface. Furthermore, diligent pool maintenance plays a pivotal role in preventing small issues from escalating into larger, more costly repairs. Understanding the intricacies of curing and maintenance processes is vital for every pool owner.
The curing process of concrete is a chemical reaction that requires the right conditions and time to develop the material's strength. Suboptimal curing conditions can lead to a host of problems, including surface cracks. When concrete or plaster is not allowed to cure properly:
Moisture Loss: Rapid moisture loss can cause the surface to dry out, leading to shrinkage cracks.
Temperature: High temperatures can accelerate the curing, preventing the concrete from developing its full strength, while low temperatures can slow down or even stop the curing process.
Insufficient Time: A rushed curing process doesn’t allow enough time for the material to solidify, resulting in a weak and crack-prone surface.
It's essential that pool builders adhere to the recommended practices including maintaining optimal moisture levels, proper temperature control, and allowing ample time for the materials to cure fully and gain the necessary strength to withstand the pressures of water and usage.
Understanding the Cracks
We know cracks can prove worrisome and unsightly. When you see them, we know you have more questions than answers.
American Dream Pool & Spa has the experience to assess the cracking taking place and can guide you on next steps to keep your pool in the best shape possible.
We proudly serve a wide area including Lincoln Hills Retirement Community, Lincoln, Rockland, Roseville, Granite Bay, Loomis, Penryn, Sheridan, and the broader Placer County.
Whether green to clean service, keeping your spa working, or performing pool repair and/or service, American Dream Pool & Spa your reliable pool expert.
