Oxidation (Rusting) of Reinforcement in Swimming Pools

Pool in high ground water table.

Pool in high ground water table.

It is not uncommon for swimming pools to be constructed in areas of high ground water. The purpose of this information memo is to ease concerns that steel reinforcing in gunite swimming pools is subject to deterioration from rusting from emersion in water due to high ground water table.

Reinforcing steel in swimming pools, when correctly installed, is well embedded within the concrete shell. This embedment, which is a minimum of three inches when the concrete swimming pool shell is cast against earth, provides good protection from corrosion. “Concrete, because its absorbed water is saturated with calcium hydroxide, is highly alkaline as is indicated by a hydrogen-ion concentration of somewhat more than 9.0 pH” 1. “Such an environment makes almost impossible the oxidation of steel and, in most instances; the demolition of old structures has shown that the steel was well protected” 1. “Steel won’t corrode in wet concrete, even in the presence of chloride ions (salt in solution), if oxygen is essentially unavailable” 2,/sup>.

Experience with thousands of steel reinforced gunite swimming pools in areas of high ground water has demonstrated that deterioration of the steel reinforcement has not been a cause for concern.


1. Dunham, The Theory & Practice of Reinforced Concrete, pg 64
2. Concrete International, American Concrete Institute, November 2001, pg 80