
Flach Industries Inc
Selkirk, NYAlbany County
concrete cutting removal, demolition, excavation, foundations, grading, hauling trucking
52 years in business

Retaining Walls project guide
Segmental block, poured concrete, timber and boulder walls built with the base, drainage and reinforcement that keep them standing.
Key facts
Rules and figures that come up in nearly every retaining walls quote, with the public source for each one.
| Fact | What it says | Source |
|---|---|---|
| Permit exemption line | Model codes (IBC 105.2) exempt retaining walls up to 4 feet, measured from the bottom of the footing, unless they support a surcharge. | International Building Code, Section 105.2 Work Exempt from PermitAs of September 2026 |
| Design requirements | IBC 1807.2 requires retaining walls to resist overturning, sliding, excessive foundation pressure and water uplift. | International Building Code, Section 1807.2 Retaining WallsAs of September 2026 |
| Seismic trigger | IBC 1807.2 adds seismic lateral earth pressure to the design of walls retaining more than 6 feet of backfill in higher seismic design categories. | International Building Code, Section 1807.2 Retaining WallsAs of September 2026 |
Project guide
Retaining walls hold back soil where a grade change is too steep to slope, and they fail for one reason far more than any other: water. A wall that lasts has a compacted crushed-stone base, a perforated drain pipe at the heel, clean gravel backfill behind the wall face, and geogrid layers tied into the backfill on anything tall. Segmental concrete block is the most common residential system and can be built by a landscape contractor up to about four feet; above that, or wherever a driveway, slope or structure sits above the wall, an engineer's design is required by most codes and the wall becomes structural work. Poured concrete and reinforced masonry walls are used for tall cuts and tight sites, boulder walls for rural and natural-look projects, and pressure-treated timber for budget walls with a shorter life.
GradeLine lists 1,591 retaining walls contractors.Compare their work and equipment, then confirm availability and service area before requesting a quote.
Listed businesses are based in Selkirk, Bemidji, Wayland, Frankfort, Dothan, Mountain City, though most crews travel well beyond their home city.
Segmental block walls typically cost $25 to $50 per square foot of wall face installed, poured concrete $30 to $60, timber $15 to $30 and boulder walls $20 to $40. A four foot tall, 50 foot long block wall therefore commonly runs $5,000 to $10,000, and engineered walls above that height climb quickly once geogrid, engineering and larger equipment are involved.
Ranges are national and approximate; regional labor rates, material prices and site conditions move them in both directions.
Segmental block walls typically cost $25 to $50 per square foot of wall face installed, poured concrete $30 to $60, timber $15 to $30 and boulder walls $20 to $40. A four foot tall, 50 foot long block wall therefore commonly runs $5,000 to $10,000, and engineered walls above that height climb quickly once geogrid, engineering and larger equipment are involved.
Send the height and length of the grade change, a photo of the slope, what sits above and below the wall, where water comes from, and the look you are after.
The main cost items are wall height and length, and whether a surcharge such as a driveway, pool or slope sits above it; engineering, excavation, base preparation, drainage and geogrid the design requires; block or material type, backfill stone, spoil haul-off and restoring the grade above and below. A site visit helps the crew see which ones apply.
Most building codes exempt walls under four feet measured from the bottom of the footing with no surcharge, and require a permit and stamped engineering above that. Walls near a property line, a public sidewalk or a stream can trigger additional setback, drainage and environmental review.
Pick a state to see the retaining walls contractors listed there. Most crews travel well beyond their home city, so confirm the service area before requesting a quote.
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Contractor directory
1,591 contractors found

Selkirk, NYAlbany County
concrete cutting removal, demolition, excavation, foundations, grading, hauling trucking
52 years in business

driveways, erosion control, excavation, foundations, grading, hauling trucking

Wayland, NYSteuben County
driveways, excavation, foundations, grading, land clearing, retaining walls

demolition, driveways, excavation, hauling trucking, retaining walls, septic systems

demolition, excavation, foundations, grading, hauling trucking, land clearing

Mountain City, TNJohnson County
driveways, excavation, foundations, grading, land clearing, retaining walls

concrete flatwork, decorative concrete, demolition, driveways, erosion control, excavation
20 years in business

demolition, driveways, excavation, hauling trucking, land clearing, paving prep


Lake Sarasota, FLSarasota County
driveways, excavation, grading, hauling trucking, land clearing, retaining walls

Leesport, PABerks County
demolition, driveways, erosion control, excavation, foundations, grading

Clayton, NJGloucester County
demolition, erosion control, excavation, foundations, grading, land clearing
67 years in business

Severn, MDAnne Arundel County
concrete cutting removal, driveways, erosion control, excavation, foundations, grading
10 years in business


Woodstock, VTWindsor County
driveways, erosion control, excavation, foundations, grading, hauling trucking
19 years in business


concrete cutting removal, demolition, driveways, erosion control, excavation, foundations

excavation, foundations, land clearing, paving prep, pond water management, retaining walls

Arlington Heights, WASkagit County
driveways, excavation, land clearing, paving prep, retaining walls, site prep

Sparks, NVWashoe County
erosion control, excavation, grading, paving prep, retaining walls, septic systems
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