Deck builders in Severn, MD

The median home in Severn was built around 1992. A deck built with a house of that age is now about 34 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 makes Severn's housing 9 years newer than Anne Arundel County as a whole, where the median home was built in 1983. Statewide, the median Maryland home was built in 1979. Among the 128 covered Maryland communities with Census data, Severn ranks #103 for oldest housing. In this ZIP code, 7% of homes were built before 1960, 25% between 1960 and 1979, 34% between 1980 and 1999, and 33% since 2000 — the single largest group dates to the 1990s.

The nearest NOAA climate station with 1991–2020 normals is Baltimore Wash Intl. AP, about 3 miles away. It records an average of 93 days a year with a low at or below 32°F — a moderate number of freezing nights. On roughly 83 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 Severn 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.

Average snowfall near Severn is about 19.3 inches a year (Baltimore Wash Intl. AP). That's enough that shoveling and ice-melt choices affect deck surfaces, and stair treads benefit from good texture and drainage.

Severn sees about 48 inches of precipitation a year, with measurable rain or snow (0.1 inch or more) on about 82 days. Good drainage between boards, clean gaps and a ledger that is properly flashed keep that water from rotting the frame.

Average summer highs reach about 87°F, and around 34 days a year top 90°F. On a deck with full afternoon sun, dark composite can get uncomfortable on those days, so test samples in the sun before choosing a color.

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

Severn has about 13,466 housing units across its covered ZIP code. 65% are single-family detached homes, 30% are attached homes such as townhouses and rowhouses, and about 5% are in buildings with two or more units. Roughly 80% of occupied homes are owner-occupied.

With a large share of townhouses, many decks in Severn are elevated rear decks over a walk-out level, built close to neighbors. Privacy screens, setbacks, guard height and HOA design approval tend to drive these projects, and repairs to shared structures may require coordinating with an association.

• Replacement and major repair: about 7,090 homes (53%) 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.
• Upgrades and expansions: about 2,466 homes (18%) 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.
• Retrofit decks on older homes: about 1,879 homes (14%) predate 1970. Here the priority is confirming that add-on decks are properly attached — or rebuilding them freestanding — before any cosmetic work.

Severn has a defined building season. Spring and early fall offer the most comfortable working weather; winter is a good time to settle the design and apply for permits. Stains and sealers generally need dry weather and moderate temperatures, so plan wood finishing for late spring or early fall.

For Severn, MD, 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, and whether your townhouse association must approve the design first. Statewide code background for Maryland is on our state page; local rules change, so the building department remains the authority.

The closest covered area is Harmans, about 2.9 miles from the center of Severn's covered ZIPs. Its median home was built in 1968, 24 years earlier than in Severn. Severn has 12 percentage points fewer detached single-family homes (65% vs. 77%), which changes how many projects are backyard decks versus compact townhouse decks. Owner-occupancy is 80% in Severn compared with 77% in Harmans. Severn's covered ZIP code span about 16.5 square miles of land with roughly 13,466 homes — about 816 per square mile, a typical suburban density where most homes have usable backyards.