Top Geotechnical Problems During Swimming Pool and Spa Construction
Updated: Mar 6, 2020
Discussing geotechnical problems and solutions with a pool contractor is a very important part of the pool building process. These issues can cause significant damage if they are not detected or considered during the planning and construction of swimming pools and spas. Geotechnical problems include cracking, differential settlement, and slope creep.
Cracks can have many causes, and luckily they are able to be repaired. Some of the most common types of cracking are caused by poor workmanship, these include horizontal cracking in waterline tile, reflective cracking, delamination, and shrinkage cracking. Ideally, the soil should be strong enough to support the pool, as well as uniform, meaning the same type of soil can be found under the entire pool. If the soil is not optimal it can also cause types of cracking, including differential settlement cracking, slope creep cracking, and expansive soil cracking.
Differential Settlement + Slope Creep
A number of soil and geotechnical issues can result in differential settlement. This occurs when a portion of the pool begins to settle while the rest of the pool remains supported and does not settle. The majority of differential settlement issues are caused by slope creep, which is a gradual downhill movement of soil and materials. This kind of structural distress is caused when the pool is located near a descending slope or hill and the soil is expansive, meaning it expands and moves when wet and can result in cracking. The risk of building a pool in this type of area can be decreased by increasing the foundation setback through deepening the pool or constructing better footing underneath the wall of the pool that is nearest the descending slope.
How to Prevent These Issues
Obtaining a geotechnical report is a very helpful step in preparing to build a pool. These
reports are used to determine the properties of the
soil and other conditions at the site, and inform the project team about what kind of issues they may need to plan for in the design. The information in these reports is referenced throughout the design process, during construction, and after the project is finished. Not having a geotechnical report done can result in unexpected issues and costly setbacks.