Decks

A deck is a structural project, not a surface project. The boards you walk on are the cheap part and the part everyone shops for. The framing underneath — posts, footings, beams, joists, and the ledger board bolted to your house — is what decides whether the deck is safe in twenty years. Deck framing is designed for a 40 psf live load plus 10 psf dead load under the American Wood Council's prescriptive deck guide, and footings must bear at least 12 inches below undisturbed grade or below the frost line, whichever is deeper.

The single biggest money decision is composite versus wood. Composite costs more up front, at roughly $28 to $40 per square foot installed against $15 to $25 for pressure-treated pine. Wood then charges you rent: it needs re-staining and sealing every two to three years at $2 to $5 per square foot, and wood decks last about 10 to 15 years against roughly 20 for composite. Run those two lines out over the life of the deck before you decide.

Do not skip the permit. Permits typically run $100 to $500, and under the standard deck construction guide a deck should not be used or occupied until final inspection and approval. An unpermitted deck becomes your problem twice: once at inspection, and again at closing when you sell.

Expect to be sold up. Railings, lighting, skirting, benches, and pergolas all get added at the quote stage, and railings alone swing from $30 per linear foot for wood to $140 to $210 for glass. Decide what you actually want before the first estimate lands, then hold the line.

How to choose

Price the frame, not just the boards

Ask every bidder to itemize framing, footings, decking, and railing separately. If a bid is cheap, the savings are almost always in the frame.

Ask for the deck's height off grade

Anything more than 30 inches above grade requires a guard, and the price of a raised deck ($25–$50/sq ft) is far above a platform deck ($10–$30/sq ft).

Compare total cost over 20 years

Wood plus staining every two to three years versus composite with almost none. Do the arithmetic once, in writing, before you pick.

Get the permit in the contract

Whoever pulls the permit owns the code compliance. If the contract makes the permit your job, that is a warning sign, not a discount.

Get three bids on anything over about $10,000

Deck pricing varies enormously by builder. Three itemized bids is the cheapest protection you can buy.