Burst Sidewall of an Above-Ground Swimming Pool

Posted by in Swimming Pools | January 23, 2017

We have observed that one of the more common causes of a split in the sidewall of an above ground pool is corrosion of the sidewall.  (For those who think swimming pool damage is only a summer issue, note the snow in the featured photo and in Figure 1.)

Figure 1 Pool sidewall burst.

The corrosion is commonly due to prolonged and repeated wetting from leakage through a penetration, such as the skimmer or a jet.

Figure 2 Corrosion emanates from leakage through penetration in sidewall.

The corrosion thins the metal, and thus, increases the stress generated by the outward pressure of the water.  Eventually, a hole or a tear creates a stress riser that causes the sidewall to “unzip” from bottom to top.  It usually starts nearer the bottom due to the more severe corrosion nearer the bottom and the higher outward pressure nearer the bottom.

Figure 3 Clean fracture of metal shows that a portion of the tear occurred recently.

A stress riser is a discontinuity in the sidewall that magnifies the stresses.  For example, grab a sheet of paper at the two short sides and try to pull it apart.  Unless you are built like Schwarzenegger, it is almost impossible to tear. Now make a two inch long tear near the middle of the long side.  Try pulling it apart again.  It is much easier to pull apart now.  The tear not only reduced the area of the paper resisting the pull, but caused a stress riser at the end of the tear.

One of my neighbors actually was able to observe the sidewall of his pool burst.  Fortunately, he saw the vinyl liner bulging outward and he exited the pool, just before it burst.  Otherwise, it could have been a wild and dangerous ride between the sharp edges of the fractured metal.