Deck Building: Materials and Construction Basics

A new deck will expand your outdoor living space and increase your home's value. If you're hiring a professional to build it, it's always a good idea to arm yourself with information before you meet with a contractor. You'll also need to do your homework. Decide what you want and do some research to learn the basic components of a deck, know the limitations of your backyard, and get familiar with the cost of materials. That way, you won't wind up with a deck that doesn't fit your needs or, worse, is dangerous.

You’ll want to get at least three estimates for the deck, and don’t just rely on online estimates. Have the contractors come to your house so they can take accurate measurements, and see if there are any obstacles that may affect the layout of your deck. To help the contractor provide you with an accurate estimate, know what you want. The first thing to ask the contractor: Are they licensed and insured?

If you plan on building your deck, be sure to research your local building codes and get a permit if needed. It is usually necessary for a deck over a particular height and square footage. Permits average about $500. You’ll also need to have your city or town building inspector or structural engineer inspect and sign off that the deck is compliant with local building codes — this is known as a certificate of occupancy. Don’t skip the permits or certificate of occupancy; not having these can come back to haunt you if you have an insurance claim or when you sell the home.

Starting from the ground up, your deck will need support framing in the way of concrete footers, support posts, beams, joists, ledger boards and the decking floor. Ground-level decks will still have framing but may be able to be built on blocks instead of posts that are secured to concrete footings. Framing is almost always built with pressure-treated wood even if your deck flooring and railing are made from other materials. Framing costs will vary depending on size, height and how the deck is attached to your home.

Most building codes allow pressure-treated posts rated for ground contact to be installed into foundation holes that are then filled with concrete. Although this method satisfies codes, over time the post is likely to rot and weaken. Many professional deck builders prefer to secure posts to concrete piers with galvanized metal connectors that hold the end of the post above the concrete base and the ground to prevent rot.

Beams and posts work together to support the weight of the deck. Posts (vertical) determine the height of the deck and, provided they're installed properly, support the beams and give the deck stability. Horizontal beams rest on top of the posts and hold up the joists. The higher a deck is, the more important the beams and posts become. But no matter how high or low to the ground your deck is, you want to be careful, thoughtful and methodical during every step of the deck-building process. On that note, your deck should primarily be assembled with galvanized decking screws rather than nails. "You have a rust element, and they (nails) aren't as strong," says landscape designer Darin Brockelbank, founder of Metro GreenScape, a company in Charlotte, North Carolina. "A lot of times you'll see bubbling in the wood and that nail will start coming out, where a screw has a wider head, and it holds everything in place and minimizes that risk."