Deck-O-Seal or Mastic Joint

Mastic Joint or Deck-O-Seal? What is it?
An old term for the joint between the coping and the deck is “Mastic Joint.” Now, Deck-O-Seal has replaced this term, but they are interchangeable.

So is it necessary at all? The simple answer is YES!

The expansion joint is the rubbery substance that seals the coping to the deck. Its purpose is to allow independent movement of the pool and the deck, prevent water from getting behind the pool shell and eroding the dirt that holds the surface of the pool and supports the deck and prevents water from getting behind or under the pool coping stones, causing cold mortar joints and freezing that can cause loose rocks and loose tiles etc.

So is it necessary at all? The simple answer is YES!

The expansion joint is the rubbery substance that seals the coping to the deck. Its purpose is to allow independent movement of the pool and the deck, prevent water from getting behind the pool shell and eroding the dirt that holds the surface of the pool and supports the deck and prevents water from getting behind or under the pool coping stones, causing cold mortar joints and freezing that can cause loose rocks and loose tiles etc.