Building Materials and Construction
Scope of the domain
Building materials and construction covers bricks, stones, cement, lime, sand, mortar, timber and steel, and the sequence of building components from foundation to roof. The exam tests sizes, classifications, bonds and foundation types.
Core rules and concepts
- Modular brick: 190 × 90 × 90 mm; with 10 mm mortar joints the nominal size is 200 × 100 × 100 mm, so about 500 bricks fill 1 m³ of masonry.
- English bond has alternate courses of headers and stretchers; Flemish bond has alternate headers and stretchers in the same course. English bond is stronger for walls of equal thickness.
- Foundation types: shallow (isolated, combined, strip, raft) and deep (pile, well). A foundation must transfer load to soil without settlement beyond limits.
- Building components: foundation, plinth, walls, columns, beams, slabs, lintels, roof, floor, staircase and parapet.
- Mortar joint thickness is normally 10 mm; mortar bonds units and distributes load.
Worked example
Find the number of modular bricks for 10 m³ of brickwork. Nominal volume of one brick with mortar = 0.200 × 0.100 × 0.100 = 0.002 m³. Number per m³ = 1/0.002 = 500. For 10 m³ = 500 × 10 = 5,000 bricks. Reasoning: use the nominal size because mortar occupies the joints; using the actual brick size alone overestimates the brick count.
Traps
Do not mix actual and nominal brick sizes. Do not call a raft foundation deep; it is a shallow foundation. Do not confuse plinth with foundation. Do not describe English bond as having headers and stretchers in every course.