Pennsylvania has some of the oldest housing in the country: the median home was built in 1966 and about 44 percent of units predate 1960. Expect plaster on lath, brick and stone masonry in older rowhouses and farmhouses, and drywall on wood studs in newer suburban homes.

median year homes were built: 1966; median year homes were built
built in 2000 or later: 15.4%; built in 2000 or later
built before 1960: 44.4%; built before 1960
single-family homes: 75.1%; single-family homes
in buildings with 5+ units: 13%; in buildings with 5+ units
mobile homes: 3.4%; mobile homes

Source: U.S. Census Bureau, ACS 2024 1-year (tables B25035, B25034, B25024)

Common wall types

Plaster on lath

Where: Older houses and rowhouses in Philadelphia, Pittsburgh, Lancaster and older boroughs; sawn lath came into general use in Pennsylvania roughly 1825-1835.

Mounting: Plaster is brittle and the lath is nailed to studs, so locate studs first and pre-drill slowly. Lag heavy TVs into studs; toggle bolts suit light loads between studs.

Brick rowhouse walls

Where: Philadelphia, Lancaster and Pittsburgh rowhouses, which have masonry exterior walls and heavy timber joists.

Mounting: Solid brick takes masonry anchors, but old mortar can be soft, so anchor into the brick itself. Interior faces are often plaster over furring.

Stone and fieldstone walls

Where: Colonial and farmhouse-era homes in southeastern Pennsylvania and stone basement foundations; sandstone is more common than limestone.

Mounting: Irregular stone needs a hammer drill and anchors set in solid stone, not loose mortar. Confirm what is behind the finish before drilling.

Wood-stud drywall walls

Where: Postwar and newer suburban homes around Philadelphia, Pittsburgh and the Lehigh Valley.

Mounting: Studs are typically 16 inches on center; lag into at least two studs. This is the easiest wall for in-wall wiring.

Poured concrete or block basement walls

Where: Basement rec rooms and home theaters statewide.

Mounting: Use masonry anchors; furred walls need anchors into the concrete, and moisture should be controlled before mounting electronics.

Metal-stud and concrete walls in apartments

Where: Mid- and high-rise buildings in Philadelphia and Pittsburgh.

Mounting: Snap toggles for metal studs and concrete anchors for poured concrete; building rules often apply.

Tips before you mount

Plaster on lath: find studs with a stud finder and confirm with a small pilot hole; drill pilot holes slowly without hammer action to limit cracking, then lag into studs with 5/16" lag bolts about 2.5" to 3" long, or use toggle bolts for light loads.
Stud walls: studs are usually 16" on center. Lag the mount into at least two studs with 5/16" lag bolts, typically about 2.5" to 3" long; a full-motion arm puts far more leverage on the wall than a flat mount, so it should never hang on drywall anchors alone.
Brick, block or concrete: use 1/4" concrete screws or 3/8" sleeve or wedge anchors with a hammer drill and masonry bit, drilling into solid brick or block face shells rather than mortar joints where possible.
Metal studs (common in apartments and condos): use toggle-style anchors such as snap toggles rated for the TV and mount weight, or have the installer add wood blocking behind the drywall.
Hiding wires: the National Electrical Code (NEC 400.12) does not allow a regular TV power cord to run inside the wall. Use an in-wall rated recessed power kit, and choose low-voltage cables rated CL2 or CL3 for in-wall HDMI and speaker runs. In brick and plaster rowhouses in-wall runs are limited, so plan on a paintable surface raceway.
Over a fireplace: check the TV maker's heat limits, since heat rising from a firebox can exceed what electronics tolerate; anchor into solid masonry or framing rather than the surface finish.
Condos and apartments: ask the association or landlord whether drilling into walls needs approval, and get the installer's certificate of insurance (COI) naming the association before work day.
Before work starts, tell the installer the wall type (studs, plaster, masonry or concrete), the TV size and weight and the mount type. These change the anchors, labor time and price.

Sources: Census Reporter, ACS 2024 1-year: Pennsylvania (B25035, B25034, B25024) · WHYY: Pennsylvania's houses are old · Builder: the row houses of Lancaster. General guidance only — your installer will confirm the right method for your wall.