Accumulation
Ice accumulation on flat roofs and certain sloping roofs may cause cave-ins. Most roofs are designed to support a maximum of 20 cm (8 in.) of ice.
You can detect roof weakening when you see:
- new cracks on inside walls and ceilings;
- that doors do not close properly;
- ceiling deflection.
If you notice these signs, temporary reinforcement work should be done immediately.