This has been a very interesting pool season. We started out with record rainfall in April & May, and now we are in the midst of an extremely dry period. August 18th is the 41st straight day of no precipitation, which is the third longest dry stretch since records have been kept (1898).
Extremes such as this can cause problems as this area tends to have expansive soil—soil that expands when it gets wet and contracts when it gets dry. This expansion and contraction of the soil causes whatever is in contact with the soil to also experience movement. This movement can damage not only pool decks, but also on house foundations, driveways, sidewalks, and patios.
Although pool builders working in this area use cushion sand and steel rebar in the construction of their pool decks, these pool decks still require your attention to help prevent raising, settling, and cracking. In addition, this movement can also damage the expansion joint (either called the mastic joint or the deck-o-seal joint) between the deck and the pool, which needs to be checked periodically.
Pool decks are not warranted against this raising, settling, and cracking. Depending on the moisture content of the soil, this raising or settling can be up to an inch or two. If a crack occurs in the deck that appears to be large enough that water can enter through the crack, it might be necessary to fill in the crack to prevent further damage.
Although it is next to impossible to completely avoid some movement in your pool deck, consistent soil moisture content is the key. Avoiding extremely wet or extremely dry soil conditions can help prevent movement. Following are some tips to help:
How to avoid having soil that is too wet
- Do not allow drainage to fall towards the pool deck.
- Try not to place sprinkler heads up against the pool deck; they can erode the cushion sand under the deck, causing the deck to move.
How to avoid having soil that is too dry-This seems to be the issue at this time.
- During extremely dry times, be sure to water you yard enough to avoid the separation between the soil and the pool deck. This separation can cause movement.
Remember that consistency is the key — try to avoid too wet or too dry. We hope that you have had a wonderful summer and that your pool is getting plenty of use.