Overview
Composite door slabs expand and contract by 2-4mm across the year with temperature. Dark colours in south-facing installations expand most. If the door was set on the edge of alignment, summer heat pushes it over.
Symptoms
- Door hard to close on hot days.
- Sticky lock only in summer.
- Fine the rest of the year.
Common causes
- Normal thermal expansion.
- Dark colour + south-facing = worst case.
When to call a professional
- For a summer-margin adjustment.
Prevention
- Allow slightly more reveal in summer (or lighter colour on south-facing installs).