Retaining Walls
A retaining wall holds back ground and water. Most failed walls in this area failed because of the water, not the ground.
Why walls fail
A block wall looks like stacking. It is not. Behind a wall that lasts there is a compacted base below frost, washed stone through the full height, filter fabric so soil cannot migrate into that stone, a drain at the base with somewhere to go, and reinforcement tied back into the slope on anything tall.
When a wall leans, bulges, or steps out of line, it is almost always because water got trapped behind it. Saturated soil is dramatically heavier than dry soil and it pushes with force that dry backfill never generates. On the slopes around the North Hills that pressure is a constant.
How we do it
Every job runs the same sequence. If something changes it, you hear about it the day we find it.
Work out what it has to hold
Height, slope above, whether anything is going to sit on top of it. That drives everything, including whether you need an engineer.
Excavate and build the base
Below frost, compacted, level. A base built wrong cannot be corrected higher up.
Lay the block and backfill as we go
Course by course, with washed stone behind each lift, not shoveled in at the end.
Drain it
Perforated pipe at the base of the stone with an outlet. This is the difference between a wall that lasts and one that leans.
Cap, backfill and restore
Caps set, the surrounding ground shaped back to meet the wall, then topsoil and seed.
What it costs
What moves the number
Walls are priced by face area, so height matters more than length. What changes the number on the block and boulder work we do:
| Work | What changes the price |
|---|---|
| Segmental block wall, under 4 feet | Block choice, access, and base condition |
| Segmental block wall, over 4 feet | Reinforcement, engineering, and drainage |
| Boulder wall | Stone size, availability, and access |
| Steps set into a wall | Tread material, run, and rise |
| Tear out and rebuild a failed wall | Disposal and how much of the base is salvageable |
In Pennsylvania a wall over four feet generally needs to be engineered, and many municipalities require a permit at that height. We will tell you where your wall lands before you commit.
We price off a site visit, not off a photograph, so you will not find a number on this page. You will get a written scope with a fixed price in it, and it will say what is included and what is not before you are asked for anything.
The work
Photographs from our own jobs.
How tall can a wall be without an engineer?
Four feet is the usual threshold, measured from the bottom of the footing to the top of the wall, and any wall carrying a slope or a load above it needs a design regardless of height. We check your local requirement rather than guessing.
Why is drainage such a big deal behind a wall?
Because saturated soil is far heavier than dry soil. Almost every leaning wall we tear out had no drain, no stone, or an outlet that went nowhere.
Can you fix a wall instead of replacing it?
Sometimes. If the base is sound and only the top courses have moved, a rebuild of the upper section can work. If the base has failed there is no repair that lasts.
Block or boulder?
Block gives you clean lines and predictable geometry. Boulder suits a natural look and can handle irregular ground. Cost is similar. It comes down to which one you would rather look at.
How long does a wall take?
A typical residential wall is several days to two weeks depending on height, access, and how much excavation has to happen before the wall can start.
Need retaining walls in the North Hills?
Send a few photos and what you have in mind. You get a straight answer about scope and what the job involves before anyone asks you for money.