Brick and Block Work
Brick and Block Work tests laying technique, joint thickness, alignment, bonding, curing and the differences between clay brickwork and concrete or AAC blockwork. The exam expects practical decisions: soak the right bricks, fill joints fully, keep courses level and cure the finished work.
Core rules
- Lay bricks on a full mortar bed with 10 mm nominal joints; fill perpends fully, especially in load-bearing and external walls.
- Soak highly absorbent clay bricks before laying so they do not suck water from the mortar; do not soak low-absorption or concrete blocks.
- Keep each course level, plumb and aligned with the line; check every few courses with a spirit level and plumb bob.
- Rake out or finish joints as specified; tooling compacts the mortar and improves weather resistance.
- Cure brickwork by keeping it moist; avoid washing out fresh mortar.
- AAC blocks use thin-bed adhesive, usually 3–5 mm, and need accurate dimension control.
Worked example
A 3 m high wall using 90 mm high modular bricks with 10 mm joints has a module height of 100 mm. Number of courses = 3,000 ÷ 100 = 30 courses. For blockwork, a 600 × 200 mm AAC block has a face area of 0.12 m2, so 1 m2 needs 1 ÷ 0.12 = 8.33 blocks; with 5% wastage, order about 9 blocks per m2.
Traps that cost marks
Dry bricks that absorb mortar water, joints much thicker than 10 mm, blocks laid without checking the first course, and no curing are frequent failures. Do not use ordinary thick mortar joints with AAC blocks; the thin-bed adhesive system depends on accurate block dimensions.
Key points
- Nominal brick joint is 10 mm; fill perpends fully.
- Soak highly absorbent clay bricks, not concrete or AAC blocks.
- A 3 m wall at 100 mm module has 30 courses.
- AAC blocks use thin-bed adhesive, typically 3–5 mm.
- Cure masonry and protect fresh joints from washing out.