Deck builders in Washington County, MN

Washington County has about 109,307 homes, with a median construction year of 1992 (the Minnesota median is 1979). Within our covered ZIP codes — about 95,290 homes — the median is 1993, close to the county as a whole.

The median home in the covered parts of Washington County was built around 1993. A deck built with a house of that age is now about 33 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.

Oldest housing: Willernie (1946), Saint Paul Park (1972) and Saint Paul (1976). In these communities, expect retrofit decks on older houses and aging decks that need structural inspection, ledger and flashing upgrades, or replacement. Newest housing: Lake Elmo (2003), Hugo (2002) and Cottage Grove (1990). Here, projects lean toward enlarging builder-installed decks, adding stairs and railings, and upgrading to low-maintenance boards.

The nearest NOAA climate station with 1991–2020 normals is Stillwater 2sw, about 2 miles away. It records an average of 159 days a year with a low at or below 32°F — a long, hard freezing season. On roughly 80 of those days the temperature climbs back above freezing, so water in wood, soil and gaps between boards repeatedly freezes and thaws.

For Washington County, that means footings must bear below the locally required frost depth to avoid heaving, and wood surfaces should be kept sealed so absorbed water doesn't split boards over winter. Synthetic decking tolerates freeze-thaw well but still needs the manufacturer's expansion gaps.

Snow is a major factor: the U Of Mn St Paul station averages about 40.4 inches a year. Framing has to carry snow load, stairs need a plan for winter use, and snow removal should be done with plastic-bladed shovels and ice-melt products the decking manufacturer allows.

Precipitation averages about 33.3 inches a year, falling on about 66 days with 0.1 inch or more — wet enough that drainage and flashing still matter, but dry spells also let wood surfaces dry out and check in the sun.

Summer heat is mild by comparison — average summer highs near 78°F and only about 4 days a year at 90°F or above — so board color can be chosen mostly on looks.

• Replacement and major repair: about 50,672 homes (46%) 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 22,006 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 17,263 homes (16%) 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.

67% of Washington County's homes are detached single-family houses and 16% are townhouses or other attached homes; 81% of occupied homes are owner-occupied. The sizable townhouse share means many elevated rear decks where re-staining is awkward, which tilts the value toward composite or PVC.

Minnesota has a statewide building code administered by the Department of Labor and Industry and enforced by municipalities that have adopted it. Before work starts, confirm with the building department for your exact address whether a permit is required, what drawings and inspections it involves, and whether an HOA must approve the design.