Maryland landscape

Baltimore has one of the densest concentrations of historic rowhouses in the country. Roughly half the city's residential stock was built before 1940, and the rowhouse blocks in Federal Hill, Fells Point, Canton, Mount Vernon, and Hampden contain thousands of homes built between 1880 and 1930. Most of those originally had plaster over wood lath on the interior, with brick party walls between units. When you renovate one, you're almost always dealing with some combination of original plaster, drywall patches added in the 1970s through 2000s, and brick that may or may not have been parged over the years.

The summer humidity makes drywall work harder than it looks on paper. Baltimore averages over 70% relative humidity from June through September, and downtown rowhouses without aggressive air conditioning can hold that moisture for weeks at a time. Joint compound that should dry in 24 hours can take 48 to 72 hours during a humid stretch. Tape that gets installed during a sticky July week can release in October if the underlying mud never fully cured.

Basements in older Baltimore neighborhoods are another common pain point. Many of these basements were never intended to be living space and have minimal vapor control between the brick foundation and any subsequent finish work. Homeowners who try to drywall over damp basement walls without addressing the moisture first usually end up redoing the work within a couple years.

Climate: Humid subtropical climate with hot humid summers (mid-80s to low 90s), cool winters (mid-30s to mid-40s), and significant seasonal humidity swings. Average rainfall around 44 inches, distributed fairly evenly through the year.
Typical Homes: Predominantly 1880-1940 in the core city rowhouse neighborhoods, with mid-century stock in outer neighborhoods
County: Baltimore City (independent)

Common Considerations in Baltimore

  • Plaster-over-lath repairs and transitions to drywall
  • Summer humidity extending compound drying times
  • Tape delamination from seasonal humidity cycling
  • Basement moisture in unfinished and partially finished spaces
  • Settlement cracking in old rowhouse party walls

Key Neighborhoods: Fells Point, Federal Hill, Canton, Mount Vernon, Hampden, Roland Park, Bolton Hill, Charles Village

Local Requirements: Baltimore follows Maryland state building code. Several neighborhoods including Mount Vernon, Federal Hill, and Fells Point are designated historic districts with additional review requirements through the Commission for Historical and Architectural Preservation (CHAP). Permits required for basement finishing.

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