Cut into 8' sections and place on top of the aluminum cross channels where your two pieces of decking meet.  If you do not seal the underside of your deck seams water will work it's way up onto your deck and ruin the bond between carpet and glue.

• Prevents water from working its way between the joints on your floor and ruining your carpet.
• Seals the joints on your pontoon flooring where two sheets of plywood join together.
• 50' roll is enough for any pontoon boat.