40 ft × 2 ft retaining wall: materials, cost and layout
Home / Sizes / 40 ft × 2 ft retaining wall
Retaining walls · size guide
40 ft × 2 ft retaining wall
What a 40 ft × 2 ft retaining wall takes to build: the materials list, when it needs geogrid or an engineer, how long it takes, and what it costs installed.
- 80 sq ft of face
- 158 blocks
- 7.7 tons of stone
Materials for a 40 ft × 2 ft retaining wall
| Item | Quantity | Notes |
|---|---|---|
| Wall face | 80 sq ft | length × exposed height |
| Wall block (6 in × 16 in face) | 158 blocks | includes one buried course and 5% extra |
| Cap units | 32 caps | glued down with concrete adhesive |
| Base: clean stone (2B / #57) | 2.5 tons | 24 in wide × 6 in deep trench, compacted |
| Drainage stone (clean #57 / 2B) | 5.2 tons | 12 in wide behind the block, full height |
| Perforated drain pipe, 4 in | 50 ft | at the base of the drainage stone, run to daylight |
| Filter fabric | 200 sq ft | between the drainage stone and the soil |
| Soil dug out | 3.9 cu yd | base trench only; more if the slope has to be cut back |
Quantities use common rules: stone at about 1.4 tons per cubic yard plus 20% for compaction, concrete sand at about 1.35 tons per cubic yard. Your stone yard can convert to their product. Base depths assume normal soil in a freeze-thaw climate; soft or wet soil needs more.
Good to know
- A 2 ft wall usually needs no geogrid in decent soil, but it still needs the full base and drainage stone. Skipping those is why short walls lean.
- When a retaining wall fails, it is almost always water, not the block. The drainage stone and pipe in the list above are the part not to skip.
Get a plan drawn for your yard
- Groundwork Design Co., our design studio, draws a 40 ft × 2 ft retaining wall for your actual yard from photos and measurements
- Scaled plan with dimensions, material list and scope any contractor can price
- Single Space plan from $349; retaining wall layout sheet +$350
- We build it ourselves in Clinton, Lycoming, Centre and Union counties
- Fixed price, 33% down, 6-month workmanship warranty
- Closest plan: Garden Wall
- Order the list above, plus 5–10% if your yard has curves
- Call 811 before you dig, two business days ahead
- Rent a plate compactor; compact every 2–3 in of base
Questions
How many blocks for a 40 ft × 2 ft retaining wall?
About 158 blocks of a standard 6 × 16 in face block, plus 32 caps. That counts one course buried below grade and 5% extra.
How much gravel do I need for a 40 ft × 2 ft retaining wall?
2.5 tons of clean 2B stone for the base and 5.2 tons of clean drainage stone behind the wall.
How much does a 40 ft × 2 ft retaining wall cost installed?
We build a 40 ft × 2 ft retaining wall in central Pennsylvania for about $6,350 ($79 per sq ft of wall face), including excavation, base, materials and cleanup. Prices elsewhere depend on local labor and stone, so the reliable way to price it where you live is a scaled plan and two or three local bids on the same plan.
How long does it take to build?
A two- or three-person crew builds a 40 ft × 2 ft retaining wall in about 2 working days, most of it digging and building the base. A careful DIY build usually takes two to three times as long.
Read next
How deep a retaining wall base should be
Timber vs block retaining walls
Why retaining walls fail
Nearby sizes
20 ft × 3 ft retaining wall
30 ft × 2 ft retaining wall
20 ft × 2 ft retaining wall
30 ft × 4 ft retaining wall
40 ft × 3 ft retaining wall
Retaining wall cost guide: real fixed prices, what moves the price →
Muthler Landscaping & Construction LLC · 913 Bellefonte Ave, Lock Haven, PA 17745 · (570) 397-9800 · PA HIC #PA212584. Installed prices are ours in central Pennsylvania (pricing v1).