Deck builders in Cottage Grove, MN

The median home in Cottage Grove was built around 1990. A deck built with a house of that age is now about 36 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 Washington County overall (median 1992). Statewide, the median Minnesota home was built in 1979. Among the 62 covered Minnesota communities with Census data, Cottage Grove ranks #34 for oldest housing. In this ZIP code, 9% of homes were built before 1960, 28% between 1960 and 1979, 31% between 1980 and 1999, and 31% since 2000 — the single largest group dates to the 1990s.

The nearest NOAA climate station with 1991–2020 normals is Hastings Dam 2, about 5 miles away. It records an average of 150 days a year with a low at or below 32°F — a long, hard freezing season. On roughly 76 of those days the temperature climbs back above freezing, so water in wood, soil and gaps between boards repeatedly freezes and thaws.

For Cottage Grove, 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 Minneapolis/St Paul AP station averages about 51.2 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 81°F and only about 8 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.

Cottage Grove has about 14,375 housing units across its covered ZIP code. 78% are single-family detached homes, 13% are attached homes such as townhouses and rowhouses, and about 9% are in buildings with two or more units. Roughly 88% of occupied homes are owner-occupied.

Detached single-family homes dominate in Cottage Grove, 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 6,616 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 3,236 homes (23%) 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 2,397 homes (17%) 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.

With about 150 freezing days a year, the building window in Cottage Grove is compressed. Design, drawings and permits are usually handled in winter so footings can go in as soon as the ground allows in spring, and finishes like stain are applied before nights turn cold in fall.

For Cottage Grove, MN, 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 Minnesota is on our state page; local rules change, so the building department remains the authority.

The closest covered area is Saint Paul Park, about 3.2 miles from the center of Cottage Grove's covered ZIPs. Its median home was built in 1972, 18 years earlier than in Cottage Grove. Cottage Grove has 6 percentage points more detached single-family homes (78% vs. 72%), which changes how many projects are backyard decks versus compact townhouse decks. Owner-occupancy is 88% in Cottage Grove compared with 77% in Saint Paul Park. Cottage Grove's covered ZIP code span about 30.1 square miles of land with roughly 14,375 homes — about 478 per square mile, a low density that usually allows larger decks and freestanding designs.