Deck climate durability

Cold climates: frost depth governs footings. Your local building official determines the specified frost line, and footings must go below it. Get that number from the building department before you accept any bid, because a deck priced on 12-inch footings in a 42-inch frost region is not priced correctly.

Snow country: check the load assumption. The prescriptive deck guide explicitly does not apply to decks that will experience snow loads, snow drift loads, or sliding snow loads exceeding 40 psf. Sliding snow off a metal roof onto a deck is a real and often overlooked load case. If that describes your house, the deck needs engineering, not a standard span table.

Coastal: corrosion is the whole design problem. Fasteners and connectors exposed to salt water or within 300 feet of a saltwater shoreline must be stainless grade 304 or 316, and all fasteners and connectors must be of the same corrosion-resistant material. Mixing metals near salt air accelerates failure at exactly the connections you can't see.

Hot and sunny: material choice and maintenance. Wood decks need restaining every two to three years at $2 to $5 per square foot, and intense sun shortens that interval in practice. Dark composite gets uncomfortably hot underfoot. Neither is a code issue — both are livability issues you should test locally before choosing.

How to choose

Get your frost depth in writing from the building department

Footings must go 12 inches below undisturbed grade or below the frost line, whichever is deeper. This is a real cost variable.

Flag sliding snow to your builder

Prescriptive design excludes snow, drift, and sliding snow loads over 40 psf. A metal roof above a deck is a design condition.

Coastal: specify 304 or 316 stainless in the contract

Within 300 feet of salt water it's the requirement, and it's expensive enough that some bidders will skip it quietly.

Don't mix hardware metals

All fasteners and connectors should be the same corrosion-resistant material.

In high sun, plan for a shorter finish cycle

The two-to-three-year restaining window at $2 to $5 per square foot is the baseline, not the ceiling.