Flat roofs · Guide
Why Flat Roofs Leak After Hail in Pretoria (and What to Do)
Quick answer
Hail can puncture or bruise torch-on membranes and crack brittle, UV-aged coatings. Hail also blocks outlets, so water ponds and finds those weak spots. After a hailstorm, clear outlets, look for dents, cuts and exposed black bitumen, and have damaged areas patched before the next storm.
Highveld summer storms often bring hail. Pretoria's flat roofs take the full impact, and a membrane that has baked in the sun for years is more brittle than it looks.
What hail does to a flat roof
- Punctures and splits in older torch-on, especially at folds and upstands.
- Loss of the reflective coating, exposing bitumen to UV.
- Ice and debris blocking outlets, so the roof ponds.
- Cracked parapet copings and flashings.
A safe check after the storm
- Look from a ladder or upstairs window if possible; don't walk on a wet roof.
- Clear outlets and gutters once it's dry.
- Photograph dents, cuts and bare patches for your insurer.
- Check ceilings below over the next few days.
Patch or redo?
Isolated damage on an otherwise sound membrane can be patched. If the roof is old, cracked all over or has had several leaks, a new torch-on or liquid system is the better spend. Storm damage is often an insured event, so ask your insurer before paying for a full roof yourself.