Allegheny County, PA / Town guide
Retaining walls in Mount Lebanon
Allegheny Wall Works connects Mount Lebanon homeowners with licensed local contractors for wall repair, replacement, and new installation, starting with a free, no-obligation assessment. Below is the local context that actually matters here: the terrain, the permit triggers, and the age of the walls.
Request a free assessmentThe ground in Mount Lebanon
Mount Lebanon was cut into rolling South Hills upland during the streetcar era, and its terraced street grid shows it: stone and block walls line front yards, driveways, and alley banks across the municipality. Many of those original walls are now approaching a century of Pittsburgh winters, and the municipality regulates wall and grading work more tightly than most of its neighbors.
The bedrock story is the same across the metro: weak red-bed claystone that loses strength when wet, under a slow-creeping blanket of colluvium. Walls doing real structural work are a common sight around Virginia Manor, Mission Hills, Sunset Hills and Beverly Heights. The landslide guide explains why that combination deserves respect.
Permit rules in Mount Lebanon
Mount Lebanon sets its own verified trigger on top of the statewide baseline, shown below exactly as the municipality states it. The contractor you are matched with handles the permit process, but knowing the trigger before you plan saves surprises.
Mount Lebanon municipal trigger (verified)
Grading permit required for walls over 2 ft. Over 4 ft, an engineer-designed wall and a 48 in safety fence are required.
Source: Mount Lebanon municipal guidance
Statewide baseline (every municipality)
PE-stamped design required over 48 in of unbalanced fill, or over 24 in with a surcharge such as a slope, driveway, or structure
Full permit details are available from the Mount Lebanon building department . The metro-wide picture lives in the Allegheny County permit guide.
Wall age in Mount Lebanon
Most of Mount Lebanon was built out in the 1920s and 1930s streetcar suburb boom, so original retaining walls here are among the oldest in the South Hills. Across Allegheny County, 28.1 percent of homes predate 1940 and the median build year is 1957 (US Census ACS 2020 to 2024 five-year estimates).
Walls age like the houses they came with. If a wall here is leaning, bulging, or shedding material, the failing wall page covers what an assessment looks for, and the hillside page covers slopes that are moving with or without a wall.
Nearby town guides