Measure Twice—Hitting the Deck: Get your Favourite Summertime Hangout Ship-Shape

👤Terry Fulljames 🕔Mar 27, 2015

Ahhh… the pleasures of a deck: warm sun, family gatherings, barbeques and the personal satisfaction of constructing one yourself. Or maybe you are just considering improving the old deck out the back. Either way, there are some finer points to know that will help you through the process.

Here in the North, unprotected wood has up to a 15-year lifespan, depending on site conditions, and non-pressure-treated wood decks require ongoing maintenance to retain moisture resistance. That said, painting or staining exterior wood can be a frustrating experience and nobody wants to be a maintenance slave to a deck.

There are several solutions to consider. First, the deck coating should be applied to 100 percent of the wood (all four sides plus the ends) to seal out moisture and prevent the water-vapour-lifting action. Using a coloured waterproofing product prevents peeling, but does not have the rich, solid colours many people desire. Adding a roof over a deck decreases moisture exposure. You could also consider using recycled plastic decking boards, which may be your recycled plastic milk jugs coming back around.

If you choose to stick with traditional wood—which deteriorates in our damp, northern climate—the best long-term solution is low-maintenance waterproof membranes, such as Duradek or Deck King. These systems are glued over plywood, protecting wood components long-term. The vinyl sheets come in various thicknesses and are often classified as good, better, best—as with most things, you get what you pay for.

Moisture can often be trapped between wood layers, which promotes decay in areas like built-up wood beams or between the joist and decking layers. As well, wood end-grain naturally draws in moisture and can be difficult to protect; this is why we often see surface boards deteriorating first. One way to solve this problem is by using pressure-treated decking planks.

Pressure-treated wood decks last longer, but require UV protection and a waterproofing agent to maximize the deck lifespan. Treated wood often splits, warps and checks—or cracks—over time. In many cases the wood treatment has not penetrated the center of the lumber, so the cut ends need to be touched up with a wood preservative like alkaline copper quaternary (ACQ)—a greener, cheaper pressure-treated lumber product used for building decks in Canada that is replacing chromated copper arsenate, which contains arsenic.

Be aware that ACQ accelerates corrosion of metal hardware like fasteners, connectors and nails, so galvanized, copper or stainless steel fasteners should be used instead. This is why pressure blocking—where joists are nailed to blocks secured to the building in favour of metal hangers—became an accepted practice in some areas.

When choosing a foundation for your deck, concrete pillars installed in the ground are the best for preventing movement due to frost, particularly if the deck is connected to two walls. Concrete deck blocks are suitable for light, simple, low decks, but have limitations in soft soil conditions or under loads such as hot tubs.

A deck can add esthetic appeal and value to your home. Combined with a beautiful view of our pristine Northwest, it can be the main reason someone buys your home or one of the reasons why you stay in this picturesque part of BC. Building your deck to be low-maintenance with long-term durability will also leave you with more time to enjoy it.