Welcome to another Q&A session where we answer questions from homeowners around Maple Valley and King County.
Today's question is:
The owner stresses that the structural elements underneath a deck are its most important part, even though homeowners rarely think about them, and he's surprised how often builders skip proper attention to this area. He explains that code represents only the bare minimum, while Euro Decks builds above code on every project. Specific practices include always using pressure-treated lumber, framing joists 12 inches on center rather than the code minimum of 16 or the sometimes-seen 24, which creates a much stronger structure without soft spots. He also requires true poured concrete footings dug below the frost line rather than cinder block footings, appropriately sized posts and beams, joist tape, and a blocking technique called baseball seam or accordion blocking to prevent side-to-side sway over time. Finally, he insists on ledgering the deck directly to the house rather than to the siding, which he considers one of the most common and problematic shortcuts he sees in the industry.
It's a phenomenal question, and as anyone could imagine, it's extremely important. It's pretty surprising how often I see people not taking this into consideration, or even worse, builders bidding or building decks without taking it into consideration. It's the bones of the deck, and there are specific ways it needs to be done. A lot of people reference code and ask if something is up to code, but the reality is that for a good deck builder, code represents the absolute bare minimum, and everything we do when it comes to framing is above code. You always want pressure-treated lumber for all your framing. Number two, what's code and what's recommended is 16-inch on-center joists, meaning the joists under the deck are 16 inches apart, and you'll see people build them even 24 inches apart, which isn't even code. But we build every deck with our joists at 12 inches on center, only 12 inches apart, which creates a much stronger floor and structure and eliminates soft spots or areas where the boards give over time. We always want true poured concrete footings, not cinder block footings, and we want to dig them deep enough to cross the frost line, so the concrete is poured deep enough that it goes past the frost line when temperatures hit freezing. We also want to use large enough posts and beams, because if they're too small, you'll have serious issues with the deck. We always like to use joist tape and what's called baseball seam or accordion blocking, a technique that keeps the deck from swaying left to right over time. If you do all of these things, pressure-treated lumber, 12-inch on-center joists, poured concrete footings, and oversized posts and beams, you'll have a deck you never need to worry about. And of course, you always want to ledger directly to the house, not to the siding. Unfortunately, we see a lot of decks attached to the siding, which should never be the case. The siding should be removed and the deck ledgered and attached directly to the house itself. If you do those things, you have proper framing, and those are the telltale signs homeowners should look for.
