The Retaining Wall "Red Flag" Checklist: 6 Signs Your Builder is Cutting Corners

If you have read our previous posts, you know by now that a retaining wall is not just a garden feature; it is a piece of structural engineering designed to hold back immense weight.

Unfortunately, the landscaping industry is full of "cowboy builders" who undercut prices by skipping the essential engineering steps that you, the client, cannot see. The result? Walls that bulge, crack, and collapse within a few years, often costing double to fix.

At DBG Projects, we believe an educated client is our best client. We want you to know what a quality build looks like.

If you have hired contractors and you see any of the following "Red Flags" happening on site, it is time to hit the pause button immediately and ask serious questions.

🚩 RED FLAG #1: They Start Building Straight onto Soil

The Scene: The team arrives, digs a shallow trench in the grass, and starts laying the first course of blocks or sleepers directly onto the mud.

The Reality: This wall is doomed. A retaining wall must sit on a solid, non-moving foundation below the frost line. If it sits on topsoil, when the ground gets wet and soft, the heavy wall will sink. When it sinks unevenly, it cracks and leans.

• The DBG Standard: We excavate deep to solid subsoil and pour a reinforced concrete footing or install a heavily compacted, wide stone foundation base.

🚩 RED FLAG #2: They Are Shoveling Clay/Soil Behind the Wall

The Scene: The wall is going up, and the builders are taking the heavy, clumpy soil they dug out earlier and throwing it right back behind the new structure.

The Reality: This is the single biggest cause of wall failure. Clay and soil act like a sponge, holding massive amounts of water. This creates "hydrostatic pressure" pushing outwards on the wall until it bursts.

• The DBG Standard: We never put soil back against the wall. We install a zone of "clean stone" (gravel with no dust) immediately behind the wall. This allows water to fall straight down to the bottom, releasing the pressure.

🚩 RED FLAG #3: There is No Drainage Pipe visible

The Scene: You look at the base of the wall before they backfill it, and there is no pipe running along the bottom back edge.

The Reality: Even with clean stone backfill, the water needs somewhere to go once it hits the bottom. Without a drain pipe, the water pools at the foundation, softening the ground your wall is sitting on.

• The DBG Standard: We always install a perforated land drain (a French drain) wrapped in geotextile fabric at the very base of the wall to carry water away from the structure.

🚩 RED FLAG #4: The Wall is Perfectly Vertical

The Scene: The builders are using a spirit level to make sure the face of the wall is perfectly, 90-degrees straight up and down.

The Reality: While it looks neat, a perfectly vertical retaining wall is structurally weaker. It is already fighting a losing battle against gravity pushing from behind.

• The DBG Standard: Most retaining walls should be built with a slight backward lean into the hill, known as a "batter." This uses gravity to help the wall push back against the earth.

🚩 RED FLAG #5: They Are Using Standard "Garden Timbers"

The Scene: The sleepers arrive for your timber wall, and they look like standard, untreated wood, or they are cutting the ends and putting them straight into the ground without re-treating them.

The Reality: Wood in contact with damp soil rot rapidly. Standard treated timber isn't enough for ground contact.

• The DBG Standard: For timber walls, we use heavy-duty sleepers that have been pressure-treated to specific user classes (UC4) suitable for permanent ground contact, ensuring they last for decades, not just years.

🚩 RED FLAG #6: The Quote Was "Too Good To Be True"

The Reality: If one quote is 40% cheaper than the others, they aren't magically more efficient. They are leaving things out. They are skipping the skip hire for the excavated soil, they aren't buying drainage stone, and they aren't paying for concrete footings.

Summary: Don't Gamble with Gravity

Watching a retaining wall being built incorrectly is stressful. Fixing one that has collapsed is expensive and dangerous.

When you choose DBG Projects, you aren't just buying a wall; you are buying the engineering expertise that ensures it stays standing. We don't hide our methods; we are proud of them.

Want it built right the first time? Contact us today for a consultation on your project.