Deck builders in Delaware County, PA

Delaware County has about 229,715 homes, with a median construction year of 1957 (the Pennsylvania median is 1965). Within our covered ZIP codes — about 91,181 homes — the median is 1960, 3 years newer than the county overall.

The median home in the covered parts of Delaware County dates to about 1960, roughly 66 years ago. Most homes from that era were built without a deck; the decks you see now were usually added in later decades, sometimes by previous owners with little documentation.

That history matters: retrofit decks are where missing ledger flashing, undersized footings and nailed-rather-than-bolted connections are most common. Before resurfacing or extending an add-on deck, it is worth confirming how it was framed and attached.

Oldest housing: Cheyney (1938), Ardmore (1941) and Havertown (1949). In these communities, expect retrofit decks on older houses and aging decks that need structural inspection, ledger and flashing upgrades, or replacement. Newest housing: Glen Mills (1995), Thornton (1990) and Newtown Square (1976). 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 Norristown, about 5 miles away. It records an average of 107 days a year with a low at or below 32°F — a substantial freezing season. On roughly 93 of those days the temperature climbs back above freezing, so water in wood, soil and gaps between boards repeatedly freezes and thaws.

For Delaware 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.

Snowfall is light — about 7.6 inches in an average year at Conshohocken — so occasional ice is a bigger concern than snow load. Textured boards and good drainage on stairs help on icy mornings.

Delaware County sees about 49.7 inches of precipitation a year, with measurable rain or snow (0.1 inch or more) on about 77 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 86°F, and around 39 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.

• Retrofit decks on older homes: about 160,622 homes (70%) predate 1970. Here the priority is confirming that add-on decks are properly attached — or rebuilding them freestanding — before any cosmetic work.
• Replacement and major repair: about 50,735 homes (22%) 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 7,865 homes (3%) 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.

44% of Delaware County's homes are detached single-family houses and 32% are townhouses or other attached homes; 70% 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.

Pennsylvania's Uniform Construction Code applies statewide and is enforced by municipalities or third-party agencies they designate. Contact your township or borough. 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.