Masonry
What this domain tests
Masonry questions check bond names, brick counts, mortar ratios, and the correct sequence for raising walls plumb and level. You should be able to sketch an English or Flemish bond mentally and know why closers are needed at quoins.
Core rules and concepts
- Modular brick 190 × 90 × 90 mm; with a 10 mm joint each brick plus mortar occupies 200 × 100 × 100 mm, so 500 bricks are needed per m³ of brickwork.
- English bond: alternate courses of headers and stretchers, strongest and most watertight, a queen closer placed next to the quoin header.
- Flemish bond: header and stretcher alternate within the same course, a three-quarter bat next to the quoin header; weaker but better looking.
- Stretcher bond suits half-brick (115 mm) walls; rat-trap bond is a hollow two-brick-thick wall saving 20-30% bricks.
- Mortar: 1:6 cement mortar for general brickwork, 1:4 for load-bearing or wet locations; joints 10 mm, fully filled, no deep furrowing.
- Rake back the day's work in a stepped manner and leave toothing for later joining; soak dry bricks before laying.
- Check plumb with a spirit level and plumb bob, line with a string, and keep the corner lead 4-5 courses ahead of the general wall.
Worked example
Bricks for a 10 m³, 230 mm thick wall. Modular volume per brick with joint = 0.2 × 0.1 × 0.1 = 0.002 m³, hence 1 ÷ 0.002 = 500 bricks per m³. For 10 m³: 500 × 10 = 5000 bricks. Add 5% for breakage and bats: 5000 × 1.05 = 5250 bricks. The same wall needs about 0.3 m³ mortar per m³, i.e. 3 m³ wet mortar.
Traps that cost marks
Counting 490 bricks using the actual brick volume instead of the modular volume; forgetting the queen closer in English bond; claiming Flemish bond is stronger than English bond; measuring wall thickness without mortar joints.