Retaining walls, terraces and paver steps
On a hillside lot, a patio starts with flat ground. Block walls and steps create it and give the yard a finished edge.
A lot of Black Hills yards slope. Rapid City's west side climbs toward Skyline Drive and the hogback, and homes in Spearfish, Lead and the hills around Custer often sit on grades that drop several feet from house to fence. A segmental block wall can hold back soil to carve out a level terrace for a patio, and paver or block steps tie the levels together.
Which wall does what?
| Wall or feature | Purpose | Notes |
|---|---|---|
| Seat wall | Freestanding seating around a patio or fire pit | Built around seat height with a cap |
| Low retaining wall | Holds back soil to level part of the yard | Gravel leveling pad, drainage stone and a drain behind it |
| Terraced walls | Breaks a tall grade change into steps | Spacing between tiers affects whether they count as one wall |
| Wall over 4 feet | Larger grade changes | Needs a building permit and an engineered design |
| Paver or block steps | Connects levels and walks | Even risers and a firm base keep them safe in ice season |
When does a wall need a permit?
Permit summaries for Rapid City say retaining walls over 4 feet tall need a building permit with an engineered design, and walls that carry a surcharge, such as a driveway, a slope or a building above, need a permit no matter the height. Building permits in the city go through the Building Services Division, which takes applications online through eTRAKiT. Outside Rapid City, ask Pennington, Lawrence, Meade or Custer County, or your city, what applies at your address. Keep in mind that a wall that doesn't need a permit still has to be built right.
How are block walls built?
- A trench with a compacted gravel leveling pad, with the first course buried
- Each course set back slightly as it rises, following the block maker's guide
- Clean drainage stone behind the block and a perforated drain at the base with a place to outlet
- Geogrid reinforcement on taller walls, where the design calls for it
- Caps glued down so they stay put through freeze-thaw cycles
Why is drainage the whole game?
Wet clay pushes harder than dry soil, and water that freezes behind a wall adds pressure every winter. Rapid City's frost depth is listed at 42 inches, and chinook thaws can turn snowmelt loose in the middle of winter. Free-draining stone and a working drain keep water from building up, and aiming downspouts and sprinklers away from the wall helps it stay straight for years.
Signs an existing wall is in trouble
- Blocks leaning out or bulging in the middle
- Gaps opening between courses or caps sliding off
- Soil or water seeping through the face after storms
- Cracks in the patio or walk right behind the wall
No two Black Hills yards are alike, so the contractor prices the job after walking the site, checking the soil, slope and access, and talking through the layout and pavers you have in mind. We don't quote prices, and any figure given over the phone is only a rough starting point.
Where we connect you with help
Common questions
How tall can a retaining wall be without a permit in Rapid City?
Permit summaries say walls over 4 feet need a permit with an engineered design, and walls with a surcharge need one at any height. Confirm with Building Services for your address.
Can wall block match my pavers?
Usually. Many manufacturers make wall block and caps in colors that coordinate with their pavers. Ask the contractor for samples.
Related services
More background: Rapid City paver patio guide.
Ready for a patio that handles Black Hills winters?
Call the number above and a paver contractor who works your side of the Hills will come look at the yard and quote the job.