No matter what material is used for the surface of a deck, the substructure is likely to be built with wood. Over time, water leaking through deck boards can cause hidden damage unless the wooden joinery of the foundation is properly protected. In fact, builders have reported that wood left exposed to the elements can begin showing signs of splitting and deterioration after just eight years.
For just a few extra dollars, contractors and homeowners can significantly extend the life of a deck’s foundation by applying waterproof flashing tape to the tops of deck joists, rim joists, beams and the ledger board. This simple step prevents moisture penetration, rot and decay, and also helps to seal around screw holes and fasteners to help prevent water seepage that can lead to rust and corrosion.
Deck flashing tape typically comes in three types: acrylic, bitumen and butyl. Bitumen, made from petroleum and asphalt, dry out over time and tend to curl up and hold water, reducing the effectiveness of the flashing. That leaves butyl and acrylic.
Butyl tape offers several advantages over acrylic-based tapes:
· It is stickier and holds longer and stronger
· It endures less stain
· It can be applied in a wide range of temperatures
· It performs better in extreme heat and has less high-temperature oozing
· It is more pliable than acrylic-based tape, allowing the adhesive to flow better around deck screws and fasteners to create a tighter seal
Butyl tape is also easier to install. Trex® Protect tapes, for instance, are available in a variety of sizes specifically designed for use on decking joists, beams, rims and ledger boards, requiring minimal cutting or trimming and limiting material waste. The self-adhesive tapes are simple to use on both horizontal and vertical surfaces and apply as a ‘cap’ (vs. wrapping) to the tops of foundational components, which allows the wood to breathe.
Trex Protect products are also guaranteed to stand the test of time. All tapes are backed by a 25-year warranty (compared with a 300-day warranty for acrylic tape). This means a substructure protected with Trex Protect will last as long as the decking it supports.
To learn more, go to TrexProtect.com.