Last Updated on October 20, 2026 by Umar Farooq
Techo Bloc walls come in about a dozen systems, but most home projects come down to six. Semma is a tapered, split-face block that bends into tight curves. Mini-Creta is the all-rounder for seat walls and planters. Raffinato is the smooth, modern block. G-Force is a lighter, hollow-core retaining block. Skyscraper uses half-ton units set by machine. Borealis looks like timber. Pick by wall height and job first, then by texture. Techo-Bloc's own chart caps its gravity walls at 18 to 35 inches before geogrid comes into it.
I read Techo-Bloc's installation guide, spec sheets and technical blog, so every figure below is the manufacturer's. And Westmount is not a wall; it's an 80 mm linear paver (9 7/16 x 3 1/8 inches).
Techo Bloc walls compared on one table
| System | Face and look | Unit height | Depth | Setback options | Anchoring |
|---|---|---|---|---|---|
| Semma | Split face, both sides | 5⅞ in | 11 in | 0° or 7.6° | Horizontal key |
| Mini-Creta / Mini-Creta Architectural | Split face, both sides | 2 15/16 or 5⅞ in | 9 13/16 in | 0° or 5.3° | Horizontal key |
| Raffinato | Smooth, both sides | 3 9/16 or 7 1/16 in | 9 13/16 in | 0° or 4.4° | Vertical key |
| G-Force | Smooth, hollow core | — | 11 7/16 in | 3.9° | Vertical key |
| Skyscraper | Smooth, oversized | multiple units | 23¼ to 48 in | 0.8° or 12.7° | Precast concrete key |
| Borealis | Wood grain | 6 in | 8 in | 0° | None (friction) |
Source: Techo-Bloc's walls installation guide. The keys are HDPE pins or strips that lock one course to the next; the front groove builds a vertical wall, the back groove a setback wall. The guide lists a 5,050 psi minimum compressive strength, against the 3,000 psi ASTM C1372 asks. If this applies to your yard, our guide to patio setback requirements goes into more detail.
Semma: the tapered block for curves
Semma's regular unit is 16 inches long at the front and 10½ at the back. That taper lets a freestanding Semma wall curve down to a 20-inch inside radius, where Raffinato needs about 89 inches. Per the Semma spec sheet, a pallet of 30 regular and 10 corner units weighs about 2,363 lb and builds about 21.74 sq ft of double-sided wall, in Chestnut Brown, Sandlewood, Champlain Grey and Shale Grey. Its 7.6° setback is the steepest of the small blocks, so it retains the most soil without geogrid: 35 inches.
Freestanding walls: Mini-Creta, Raffinato and Semma
Freestanding, Mini-Creta, Raffinato and Semma all max out at 29 7/16 inches exposed, cap excluded. Borealis stops at 24 inches.
- Mini-Creta mixes 3-inch and 6-inch courses for a random-stone face. Our Mini-Creta guide covers its sizes.
- Raffinato comes in 90 mm and 180 mm heights for a clean, contemporary face. See our Raffinato guide.
Freestanding walls get adhesive throughout. On retaining walls, Techo-Bloc's blog wants it only on corners, the last course and under caps; gluing everything "removes its flexibility and actually weakens its performance," and is up to 20% slower. The extra adhesive costs you twice.
G-Force and Skyscraper for bigger retaining jobs
G-Force is built only as a setback wall (3.9°), which gives it a 32-inch gravity limit. Skyscraper units weigh up to half a ton and need mechanical installation. It's a contractor product, not a weekend one, however good the weekend.
How tall a Techo-Bloc wall can go without geogrid
These are total heights, assuming good soil, drainage and nothing heavy above. Two things people miss:
- Burial counts. At least 10% of the height goes below grade, never less than 6 inches, so a 30-inch Mini-Creta wall shows about 24 inches.
- Vertical costs height. Built plumb, the same blocks retain 18 to 24 inches.
Many towns require a permit above a set height.
What every Techo-Bloc wall sits on
- A trench with 6 inches of room in front and 12 inches behind.
- A compacted 0-3/4 inch crushed stone leveling pad, at least 6 inches thick.
- A 4-inch perforated drain behind the first course.
- At least 12 inches of clean ¾-inch stone behind the blocks, backfilled every 8 inches.
Our raised paver patio guide covers fill behind the wall.
Let the wall's height and job pick the block
My opinion, backed by Techo-Bloc's own chart: choose by the height you need to retain, then by texture. Under about 2 feet, pick the look. At 2½ to 3 feet, the setback blocks (Semma, G-Force, Mini-Creta) have margin left. Above that, you need an engineer. A beautiful wall that leans over the lawn by its third spring is really a very expensive planter.
FAQ
What is the difference between Techo Bloc Semma and Mini-Creta?
Semma is a tapered unit that curves to a 20-inch inside radius and retains up to 35 inches. Mini-Creta mixes 3-inch and 6-inch courses and retains up to 30 inches inclined.
Do Techo Bloc walls need glue?
Only on corners, the top course and under caps, plus every course of a freestanding wall.
How high can I build a Techo Bloc retaining wall myself?
The residential chart tops out at 18 to 35 inches of total height, depending on block and setback. Taller walls need geogrid and an engineered design.
