What is the roof made from?
Felt, corrugated sheets, membrane systems and older materials are all found on garages. Identify the covering before choosing a repair method.
Check perimeter details
Where the garage joins the house or boundary wall, water can enter at the upstand. At the free edges, damaged trims allow wind beneath the covering.
Sagging and standing water
Timber decking can soften and deflect after repeated wetting. If a pond keeps returning in the same place, look at the support beneath as well as the waterproof layer.
Older sheet roofs
Some older garages contain asbestos cement sheets. Do not drill, break or remove suspected asbestos material without suitable identification and precautions.