Walls and Structural Elements
Walls and Structural Elements tests load-bearing versus non-load-bearing walls, piers, lintels, beams, columns, damp-proof courses, movement joints and the effect of openings on stability.
Core rules
- Load-bearing walls carry loads from above and need proper bonding, thickness and restraint; non-load-bearing walls carry only their own weight and finishes.
- A damp-proof course at plinth level stops rising damp; it must be continuous and not bridged by plaster or debris.
- Lintels span openings and need adequate bearing, commonly at least 150–200 mm each side unless design says otherwise.
- Chase walls only within permitted depth and never cut through reinforcement or load-bearing piers without approval.
- Provide movement or expansion joints where specified; do not fill them with rigid mortar.
Worked example
A 10 m long DPC in a 230 mm wall is specified as 50 mm thick cement concrete. Volume = 10 × 0.23 × 0.05 = 0.115 m3. At a nominal 1:2:4 mix, order materials for at least 0.115 m3 plus wastage, and keep the DPC continuous across door thresholds and junctions. A break in the DPC allows rising damp to bypass the barrier.
Traps that cost marks
Treating a partition as load-bearing, making deep horizontal chases, removing temporary props too early, or interrupting the DPC at a threshold are frequent errors. A lintel with too little bearing can crack the wall above the opening.
Key points
- DPC must be continuous at plinth level and not bridged.