Solid concrete blocks are named by length × height × thickness. The thickness — the last number — decides what the wall can do. Here are the five sizes we make and how builders typically use them.
Sizes and blocks per square metre
| Size (L × H × T) | Wall thickness | Approx. per m² | Typical use |
|---|---|---|---|
| 15" × 8" × 6" | 6 inch | ≈ 12 | External walls, load-bearing walls, compound walls |
| 15" × 8" × 4" | 4 inch | ≈ 12 | Internal partition walls |
| 15" × 6" × 6" | 6 inch | ≈ 16 | Where a lower course height is needed |
| 12" × 8" × 6" | 6 inch | ≈ 15 | Shorter runs and closing gaps |
| 9" × 8" × 8" | 8 inch | ≈ 20 | Thicker walls and heavier loads |
Quantities include a 10 mm mortar joint. Add about 5% for breakage and cutting.
Choosing the thickness
If a wall is load-bearing, follow the thickness on your structural drawing.
- 6 inch — the usual choice for outer walls of houses and for compound walls.
- 4 inch — for internal partitions that carry no load. Lighter and quicker to lay.
- 8 inch — when the structural engineer specifies a thicker wall.
Why solid blocks over bricks?
- One 15" × 8" block covers the area of several bricks — fewer joints and faster laying.
- Less mortar per square metre of wall.
- High compressive strength for compound and load-bearing walls.
Need a quantity worked out?
Send your wall lengths and heights on WhatsApp and we will tell you how many blocks of each size to order.