Most people understand that to keep their swimming pool and spa looking great they have to regularly maintain their filter, water chemistry, and vacuum the interior surface of their pool. But when was the last time you inspected your decking mastic?
Mastic is the rubbery material that covers an isolation joint separating the coping of your pool from your decks. See the diagram below. Its purpose is to allow the decks to move independently of the swimming pool structure, thus minimizing the potential for damage to the pool tile, coping, and structural shell. Mastic also prevents water from going down the joint and under the decks when it rains, or water splashes out of the pool from swimmers.
With time and exposure, mastic loses it's elasticity and cracks. Once the mastic has cracked it no longer seals out water and you run the risk of saturating the soil beneath the decks. This can cause your decks to raise and crack more than normal, leaving you with elevation differences between your pool coping and the decks.
Mastic replacement is relatively inexpensive compared to the alternative of damaged decking. Do-it-yourselfers can find replacement products online or at their local pool supply stores and the internet is full of good "How To" videos. Or, if you'd rather just hire someone to do it, there are many small companies that perform this service.
Whatever you do, don't overlook this small maintenance item, because ignoring it could create expensive damage to you beautiful outdoor resort.