Where the water comes in
- Cracks in the roof slab.
- The joint where the roof meets the wall.
- Around pipes and vents that come through the roof.
- Blocked outlets, so water stands on the roof.
- An old coating that has cracked or lifted.
The usual steps
- Clean the roof and remove loose old material.
- Fill the cracks and seal the joints.
- Put a waterproof coating or sheet on the roof. Which one suits your roof is for the mistri to say after seeing it.
- Correct the slope and clear the outlets, so water runs off.
- Let it dry as long as the material needs before anyone walks on it.
Stay safe
Roof work is work at height. Do not go up on a wet or slippery roof, and do not work near an edge without a wall. Keep away from electric wires that pass near the roof. Leave the work to a trained mistri. Inside the house, switch off the power near any ceiling where water is dripping, and do not stand under a ceiling that is sagging or cracking.
If a ceiling is sagging, bulging with water or has wide cracks, move everyone out of that room and call a qualified engineer before anything else.