Mastic (Deco-Seal) is the material between your coping and deck of your pool. It is a wear item and usually lasts 3-4 years. This material is designed to prevent water from getting under your coping and causing freeze damage. When the material starts to become hard and brittle or cracks and separates it is time to replace it. Dallas Stone Sealers will cut out our old mastic, clean and prepare the joint and pour new mastic and then top with sand. Mastic is considered a maintenance item and usually lasts from 2-4 years depending on deck movement. It is available in a variety of colors but tan and gray are the most common.
Often overlooked, the barrier is very important because it not only seals out water and keeps it from penetrating your wood. It also works like a shock absorber. It allows the deck boards to move back and forth against the solid structure of the pool, to reduce cracking, chipping and further damage.
Mastic won’t last very long. As soon as it cracks, it loses it’s waterproofing ability and is no longer useful.
As water seeps through the mastic, your decking boards swell. After some time the entire deck can lift upwards creating a lip at the edge of the pool. That’s structurally unsound and dangerous.