Why Do Concrete Swimming Pools Crack?

Swimming Pool

Concrete swimming pools in the ground are durable and can last decades. Gunite, shotcrete, and concrete walls can develop cracks over time. Although small shrinkage cracks can be a problem, if cracks become large enough to insert a dime into them, the shell may be compromised. Here are reasons concrete pools might crack.

  • Installation on the hillside: Gravity causes soils to slowly climb downhill. Therefore, a pool built on a hillside is best avoided.
  • Changes in soil moisture: Flood conditions can cause soil to swell and lift the shell up. Alternately, soil that is normally wet may dry out and shrink in drought conditions, causing the pool’s settlement and cracking.
  • Hydrostatic pressure: A concrete pool can be slightly lifted or tilted by changes in groundwater levels. The shell could crack if the movement is too large.
  • Poor installation: The shell can develop air pockets or voids if it isn’t properly laid out using stakes and forms.
  • Poor plumbing installation: PVC pipes should run through concrete shells to connect pool returns. However, they should be minimized. The pool floor plumbing, as well as horizontal pipes within the walls, can cause cracking and weaken the pool.
  • Concrete pools require at least 14 days for a cure: Cracking can be caused by rushing the concrete pouring or pouring it too hot.
  • Incorrectly applied expansion joint: Concrete pools have an expansion joint that compensates for temperature expansion and contract. If the joint isn’t true or becomes clogged with debris, it could cause horizontal cracks to form in the tile band.

Beach to Bay Dive Services started in early 2019 as a commercial dive service. Our team continues to provide our customers with the peace of mind of knowing that each project will be performed correctly from conception to completion at a fair cost. Our reputation has been and continues to be our best advertisement. Recently, Beach to Bay Dive Services has transitioned to Beach to Bay Divers and Pools. Our experienced pool technicians provide a level of service and repairs that assure our pool customers have that same peace of mind as our dive service.