mastic2-smallMastic Sealant Repair or Deck-O-Seal?  What is is???
An old term for the joint between the coping and the deck is “Mastic Joint” or “Deck-o-Seal”

The expansion joint is the rubbery substance that seals the coping to the deck. This allows the independent movement of the pool and the deck, which prevents water from getting behind the pool shell and eroding the dirt that holds the shell of the pool, which can also cause loose stones and loose tiles and other structural damage.

DECK-O-SEAL is used for caulking and sealing joints subject to concrete movement to provide a firm, flexible, weather-tight seal.  It is ideal for sealing joints on swimming pool decks. It is applicable for both interior and exterior use.


  • Highly resilient with excellent recovery characteristics
  • Provides permanent and uniform watertight seal.
  • Prevents uncontrolled cracking by allowing expansion and contraction during temperature changes.
  • Stays flexible … won’t become brittle or crack due to ultraviolet exposure.
  • Resists abrasion, weathering and moisture … elevated temperatures will not cause discoloration.
  • Not affected by today’s pool chemicals.
  • Retains joint soundness in service once it’s cured and can be stretched or compressed up to 25%.

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