Stone pavers, stamped concrete, fieldstones and even brick, but nothing seems more American than a great deck to fire up the grill and enjoy your backyard. According to NADRA, more than 2.5 million new or replacement decks are constructed every year. Composite decking materials and more sophisticated treated lumber decking enable a deck to last longer than ever before. Unfortunately, there is one simple and easy method to make your deck last even longer. It’s hidden under that beautiful deck surface – waterproofing protection for the deck structural support system and posts.
Most deck support systems are manufactured with treated lumber. Over time, the constant exposure to rain, snow and moisture will eventually leave the wood susceptible to rot and decay. One way to extend the life of these critical elements is by installing a self-adhering waterproofing membrane at these critical points:
Ledger Boards
The ledger board, which is mounted to the building structure, carries a lot of the deck load and is area that can benefit from additional waterproofing. By installing a flashing membrane over the ledger board, it will prevent water, debris and moisture from accumulating behind this hard-to-reach area.
Joist Ends
ACQ-treated lumber can potentially cause metal components to corrode. By installing a flashing membrane, it provides a protective barrier between the wood, metal joist hangers, and the support beam brackets.
Joist Tops
The top of horizontal joists is especially prone to water damage from ponding water. Installing a waterproofing membrane across these top surfaces will create a permanent moisture barrier. The second problem area with joist tops is the fasteners used to support the deck top are nailed or screwed into the joist creating a direct line into the joist for water to penetrate.
Posts
When posts are buried in the ground, there is a lot of moisture in the soil which causes fungal growth that can attack and weaken these critical components. Using a waterproofing membrane just below the surface eliminates the concerns of structurally damaged posts. Most waterproofing membranes can also be used on post bottoms when they are set on a concrete pad or attached to a metal bracket.
Finding the Right Membrane
There are a variety of waterproofing products on the market today. To ensure the best protection available, make sure the membranes offer these attributes:
- Self-Adhering – these types of membranes are easy to use, handle and install. No special tools, coatings or adhesives are needed, so it is ideal for both a professional and DIY homeowner to use. The only tools needed are a sharp utility knife and a hand roller to roll the entire surface of the membrane. The key to self-adhering membranes is to get the maximum amount of contact of the membrane to the wood’s surface.
- Self-Sealing – this is the most important attribute that a waterproofing membrane must have. Decking requires a lot of fasteners such as nails and screws. A self-sealing membrane will seal around the fastener to create an effective waterproof barrier.
- Service Temperature – make sure that the membrane selected will meet the anticipated variance in temperatures the deck will be exposed to during the course of a year. Also pay close attention to the minimum installation temperature to avoid any installation problems during cool or colder conditions.
- Warranty – pay attention to the published warranty of each product under consideration. The warranty is often a representation of how well the product is constructed.
MFM Building Products manufactures DeckWrap PowerBond, a 25-mil self-adhering and self-sealing membrane specially designed for use with decking and posts. The product can be used with treated, untreated and synthetic wood types. To learn more about DeckWrap PowerBond or to request a FREE sample, please visit www.mfmbp.com/deckwrap or call MFM Customer Service at 800-882-7663.
