It’s a lot of work; here’s how to make your deck last.
1. Install your concrete footings below the frost line. Sure, it’s only a deck, but heaving or shifting can ruin all the hard work you put into it.
2. A slope helps shed water. Particularly if you’ve built a solid-floored deck using tongue and groove boards, slope the deck away from the house 1/4″ per foot.
3. While joist hangers can do the trick, you’ll get the strongest, longest-lasting support by sitting all joists on beams. Use hangers to attach the joist to the ledger board on the house. And make sure you use galvanized hangers to prevent rust.
4. To make sure your ledger board stays put, attach it directly to the house framing or foundation — not just to the siding. If you’re attaching it to the concrete foundation, install spacers between the concrete and the ledger to prevent rot. If you’re installing it to the house framing, use flashing to protect the ledger from collecting water on top.
5. No matter what wood you’re using for the bulk of the deck, use pressure treated for any framing which touches concrete or is within a foot of the ground.
6. For spots you’re going to have a tough time getting at and repairing down the road, use special care, including wood preservative coatings and stainless steel fasteners.
7. Plan ahead for your railings. The sturdiest are built on the deck’s actual support posts. Extend these through the deck, then cover and trim them out with finish material, so they look better. If you can’t extend the posts, attach the railing posts to the joists with 1/2″ zinc-plated machine bolts.