Deck builders in Snohomish, WA

The median home in Snohomish was built around 1991. A deck built with a house of that age is now about 35 years old — the stage where first-generation pressure-treated decks commonly need major repair or replacement.

Decks built before 2004 were very likely made with CCA-treated lumber, which was phased out of most residential uses at the end of 2003. That doesn't make an existing deck unsafe, but old boards shouldn't be burned, and demolition debris should be disposed of according to local rules.

That is about the same as Snohomish County overall (median 1990). Statewide, the median Washington home was built in 1985. Among the 34 covered Washington communities with Census data, Snohomish ranks #24 for oldest housing. In these ZIP codes, 12% of homes were built before 1960, 21% between 1960 and 1979, 35% between 1980 and 1999, and 32% since 2000 — the single largest group dates to the 2000s.

The nearest NOAA climate station with 1991–2020 normals is Monroe, about 5 miles away. It records an average of 60 days a year with a low at or below 32°F — a moderate number of freezing nights. On roughly 57 of those days the temperature climbs back above freezing, so water in wood, soil and gaps between boards repeatedly freezes and thaws.

Frost is less severe in Snohomish than in northern states, but footings still have to meet the local frost-depth requirement, and freeze-thaw cycles are enough to work loose nails and open checks in unsealed wood.

Snowfall is light — about 3 inches in an average year at Monroe — so occasional ice is a bigger concern than snow load. Textured boards and good drainage on stairs help on icy mornings.

Moisture is the main enemy here: about 50.8 inches of precipitation fall on roughly 119 days a year. Decks stay damp for long stretches, so ventilation underneath, joist-top protection, flashing at the ledger and moisture-resistant boards matter more than usual.

Summer heat is mild by comparison — average summer highs near 72°F and only about 2 days a year at 90°F or above — so board color can be chosen mostly on looks.

Budget, upkeep tolerance and sun exposure on your particular lot still decide the final choice between these options.

Snohomish has about 25,127 housing units across its covered ZIP codes. 84% are single-family detached homes, 2% are attached homes such as townhouses and rowhouses, and about 14% are in buildings with two or more units. Roughly 84% of occupied homes are owner-occupied.

Detached single-family homes dominate in Snohomish, so most decks are backyard decks attached to the rear of the house. That gives more freedom on size, layout and stairs, and makes a well-planned deck one of the most-used rooms of the home.

• Replacement and major repair: about 11,939 homes (48%) were built between 1970 and 1999, the age group whose original or early add-on decks are most likely to have worn-out framing, connectors and boards.
• Retrofit decks on older homes: about 5,103 homes (20%) predate 1970. Here the priority is confirming that add-on decks are properly attached — or rebuilding them freestanding — before any cosmetic work.
• Upgrades and expansions: about 2,578 homes (10%) were built since 2010. Their decks are usually sound but small or builder-grade, so enlarging the deck, adding stairs and switching to composite or upgraded railings are common.

Snohomish's milder winters — about 60 freezing nights a year — allow construction through most of the year. Spring and fall are still the busiest seasons, so booking early helps.

For Snohomish, WA, ask the permit office whether your deck needs a permit based on its size, height and attachment to the house, which drawings and inspections are required. Statewide code background for Washington is on our state page; local rules change, so the building department remains the authority.

The closest covered area is Everett, about 8.8 miles from the center of Snohomish's covered ZIPs. Its median home was built in 1985, 6 years earlier than in Snohomish. Snohomish has 35 percentage points more detached single-family homes (84% vs. 49%), which changes how many projects are backyard decks versus compact townhouse decks. Owner-occupancy is 84% in Snohomish compared with 54% in Everett. Snohomish's covered ZIP codes span about 152 square miles of land with roughly 25,127 homes — about 165 per square mile, a low density that usually allows larger decks and freestanding designs.