General information for homeowners, not legal or engineering advice. Permit rules change and vary by municipality; check with the City of Pittsburgh Department of Permits, Licenses, and Inspections or your township or borough before you build.
Not every slope needs a wall. But in a hilly city like Pittsburgh, a lot of yards reach the point where grass and mulch can’t hold the ground in place anymore. Here’s how to tell when a retaining wall makes sense, when something simpler might do, and how to spot a wall that’s starting to fail.
Signs your yard needs a retaining wall
- Soil keeps washing down onto your driveway, patio, sidewalk or the street after heavy rain.
- The slope is too steep to mow or use, and you’d like a flat area for a patio, garden or play space.
- The driveway or parking pad is cut into a hill and the bank beside it keeps slumping.
- Water runs toward the house from a hill above it.
- Exposed roots, gullies or bare patches are spreading on the slope.
- An old wall is failing and the ground behind it needs holding back again.
When a wall might be overkill
On a gentle slope, regrading, ground-cover plants, erosion-control fabric or a simple drainage fix may be enough. A good contractor will tell you if you don’t need a full wall. If water is the main issue, read about drainage behind walls.
Signs an existing wall is failing
- The top of the wall is leaning out, away from the hill
- A section is bulging or bowing
- Cracks, gaps or loose blocks and caps
- Soggy ground, seeping water or soil washing out at the base
- Rotting timbers on a railroad-tie wall
Small problems are often repairable. See retaining wall repair andretaining wall replacement.
Why Pittsburgh is hard on walls
Steep ground, clay soil that holds water, and winters that freeze and thaw over and over all add pressure behind a wall. Parts of the region are also prone to landslides on steep hillsides. If your slope has already moved, or you see cracks in the ground above it, mention that in your quote request; some jobs need an engineer to look first.
Before anyone digs
Pennsylvania law requires a call to PA 811 (Pennsylvania One Call) before digging so underground utility lines can be marked. Your contractor normally handles this, but it’s worth asking. Taller walls may also need a permit: seeretaining wall permits in Pittsburgh.