I have frequently been asked about whether or nor is ok to empty a swimming pool and leave it empty.
For the purposes of this article I will be discussing a “gunite” or more properly “shotcrete” inground swimming pool.
Fiberglass pools and vinyl liner pools should heed the same advice though for slightly different reasons
It is not advisable to empty your concrete swimming pool for longer than a day or two if required for maintenance reasons. There is a high probability of structural failure of the pool if it is left in the “empty” state. In the case of a fiberglass pool or vinyl liner pool please contact your installer as emptying the pool may cause immediate and irreversible damage to the pool.
The reason for this is, pools are engineered as “retaining walls” to retain the pressures of the soil behind the walls. These pressures are significant and capable of literally crushing concrete. In the Engineering calculations the weight and counter resistance of the water against the walls are factored in. In other words the “water” itself contributes substantially to the structural integrity of the pool. By leaving the pool empty the soil pressures will exceed the design strength of the pool walls making them subject to structural failure.
The reason engineers use this methodology are: it is a sound method, it is a proven method, as long as the water remains the engineering requirements are met in full, and it saves a significant cost over engineering the pool and constructing it to remain empty. (Thousands of dollars in construction savings)
So do not leave your pool empty, the damage could easily be in the tens of thousands of dollars to repair.
Rex Richard, is an expert in swimming pool construction, pool service, pool repair, and pool retail, and a consultant to the pool industry. Rex is also the founder of the pool industries largest social network, The Pool Genius Network.