Purpose and how to use this page
This page sets expectations for retaining wall design limits, drainage standards, site conditions, and when engineering is required.
Definitions and notice timing rules used across policies are available on our main policies overview page. We do not restate them here.
What retaining walls are designed to do
A retaining wall is designed to retain soil and manage drainage behind the wall.
Performance depends on soil conditions, drainage, and loads. We do not promise “zero movement” in all conditions.
Drainage standards behind walls
Drainage behind a wall matters because it helps reduce water pressure there.
The 12–18 inch drainage rule
For any segmented block or masonry wall over ~12–18 inches:
- Free-draining backfill (washed stone) directly behind the wall
- Perforated drain pipe at the base with appropriate outlet(s)
Walls over 1 foot: engineered drainage
Walls over 1 foot in height are installed with engineered drainage (drain rock + perforated pipe) unless otherwise specified in writing.
Exceptions only when following manufacturer instructions or stamped engineered plans that specify something different.
Outlet locations depend on site conditions. We confirm the outlet approach during planning or on-site evaluation.
Base and compaction standards
- We install suitable compacted base material appropriate for the wall type and soil conditions.
- Compaction is performed in lifts to create a stable, well-compacted foundation.
- For higher-risk or large projects, installation is performed in accordance with manufacturer specifications and/or engineered requirements, as applicable.
When engineering is required
Up to 3–4 feet total exposed height: typically designed/installed using manufacturer specs and local best practices.
Over 4 feet total exposed height OR any wall supporting structures/vehicles/steep slopes:
- Requires a stamped engineered design, or we may decline the project.
Engineering is also required when the wall is:
- Near a building foundation or pool
- Retaining a steep slope or parking area
- Requested to handle vehicle loading near the wall
Engineering options (yours vs ours)
You may choose one of these options:
- You provide a stamped engineered plan, or
- We use our engineering partners (preferred for coordination and communication).
Normal vs not-normal movement
Depending on soil and weather conditions, minor settling or cosmetic changes may occur.
Report any of the following promptly with photos:
- Significant movement
- Bulging or leaning
- Unexpected cracking
- Drainage problems (washouts, pooling behind the wall, outlet concerns)
We do not promise free rebuilding. Some issues may fall outside the scope of workmanship, depending on the cause. Use the reporting process below and see the claim framework on our service warranty page.
Customer responsibilities
- Do not add heavy loads near the wall (e.g., vehicles/equipment) unless they are engineered for it.
- Do not alter grades or drainage behind the wall after installation.
- Keep wall outlets (if present) clear.
- Disclose known private lines or site constraints before work starts (see Damage, Risk & Liability Policy).
How to report a concern
- Send photos (wide + close-up) plus a short description of what you see (leaning, bulge, cracking, washout).
- We review and respond with next steps.
- If needed, we schedule an inspection.
- We provide a resolution plan + timeline.
Notice timing rules: Policies. Written notices sent outside business hours are treated as received at 8:00 AM CT on the next business day. Please confirm receipt.
Related policies
- Warranties Policy (claim framework)
- Damage, Risk & Liability Policy (site conditions, private lines, acts of nature)
- Change Orders & Scope Policy (hidden conditions, written approvals)
- Policies (definitions + notice timing)
What this policy does not cover
- This is not a blanket guarantee against extreme weather, soil movement, flooding, or third-party modifications.
- Engineering-required walls must follow stamped plans. Any deviations require written approval (see Change Orders & Scope Policy).