Ask the Architect

Don’t cut corners on the deck

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Q. My landscaper has taken a long time to rebuild our backyard deck, and now we’re wondering whether he can do the work in the winter. It was supposed to be done last fall, but he never showed. We’re leaving the foundation, but have to replace some beams that look rotted. Someone told me that the deck boards should be 2x4’s, and that they can warp if not nailed correctly, but I don’t know what that means. He also said that if the boards are put on the deck in cold weather, they’ll need to be spaced more so they don’t push up against each other when they swell when it gets hot. Is that so? What do you advise?

A. There are multiple facets to any construction project, large or small. It’s good that you asked questions first. You need to understand what materials are being used, their characteristics and how they perform long-term. Many people focus on the finished project and how great it looks right when it’s done, without knowing that in a short time, some materials will begin to react and shouldn’t have been used, especially if there’s something better. You also need to know what exposure to weather conditions will do, how the materials will be attached to one another, and whether materials need special handling and cost comparison.
Starting with cost, it’s never advisable to build based only on the cost of materials if you’re looking to just get something built. Better, long-lasting materials cost more but have greater value. Using thicker materials, like 2-inch by 4-inch-thick boards, isn’t necessary, and unless you choose the right species, you defeat the purpose.
You’re much better off using engineered deck boards, synthetic with a wood look, than real wood. It’s better to have synthetic boards that are made to fit next to each other, with pre-made tongue and groove, where the tongue has spaced holes that allow the deck to drain but are hidden from sight as the boards interlock. The tongue of the boards is made to receive stainless or galvanized deck screws that fasten at an angle as they are drilled downward. Don’t use other kinds of screws. Use deck screws, made for this purpose. The hidden screw head will allow for a smooth surface that you can walk barefoot on without popped-up screw heads, and the angle drilling means the screws are going in to the treated wood joists, below, across the wood grain, so the screws are tighter and won’t easily move or release.

Synthetic boards are usually around 1¼ inches thick, often referred to as 5/4 decking. The engineered synthetic varieties cost more than real lumber, but last many times longer without needing expensive staining or surface treatment other than gentle washing. If someone offers to power-wash, be very concerned. High-pressure washing can ruin the material surface very quickly. Spend now, save later.

© 2019 Monte Leeper. Readers are encouraged to send questions to yourhousedr@aol.com, with “Herald question” in the subject line, or to Herald Homes, 2 Endo Blvd., Garden City, NY 11530, Attn: Monte Leeper, architect.