Quality Control, Defect Rectification and Site Clean-up
Inspect, record, rectify, clean
Quality control is a cycle: check the work against the specification at each stage, record what you find, rectify defects at the right time, and leave the site clean. This domain tests defect identification, causes and remedies, and the standard of finish expected.
Core concepts to know
- Standards of finish: compare the surface against the specification and the agreed sample; check flatness with a rule or straightedge, and check plumb and level on beads and angles.
- Common defects and causes: hollow or drummy plaster (poor bond, dusty background), cracking (rich mix, rapid drying, movement), crazing (fine shrinkage cracks), blistering or popping (contamination, unsound particles), and poor finish (over-trowelling, wrong timing).
- Rectification: cut back to sound material, prepare the background, and patch with a compatible mix; feather edges so the repair blends. Repairs to decorative finishes must match texture and colour.
- Curing and protection: protect fresh work from draughts, sun and other trades until set.
- Site clean-up: remove offcuts and packaging, contain and dispose of slurry and washout correctly, clean tools, and leave access routes clear.
- Records: note defects, causes and actions; this supports handover and shows the work was checked.
Traps
A frequent distractor is painting or filling over a hollow or cracked area rather than cutting it back. Another is cleaning tools into a drain, or leaving washout to set in a drum.
Worked rule of thumb
When you find a defect, ask three things in order: what caused it, will the same cause affect the rest of the area, and what is the correct repair method? Fixing the symptom without the cause means the defect returns - and it will be your second repair, not your first.