Common sources of leaks
- Penetrations: plumbing vent boots, exhaust vents and swamp cooler or HVAC curbs. Rubber and sealants dry out in the sun.
- Flashing: where the roof meets a wall, chimney or skylight, and along valleys.
- Broken or slipped tiles: from foot traffic, wind, or settling.
- Lifted or missing shingles: wind gets under weakened seal strips.
- Worn underlayment: under a tile roof, the tile sheds most of the water but the underlayment is the real waterproof layer.
- Ponding on low-slope roofs: standing water on foam or coated roofs speeds up wear at seams and low spots.
What a repair visit usually looks like
- Inside first: the roofer looks at the stain, the attic if accessible, and any daylight or wet framing.
- On the roof: checks penetrations, flashing, valleys and the field of the roof uphill of the leak.
- Explains the fix: for example, replacing a vent boot, resetting flashing, swapping broken tiles or re-sealing a foam seam.
- Written price before the work, plus a note on anything else that's near the end of its life.
Small problems worth fixing early
In a dry climate, small leaks don't always show up right away. Water may soak insulation or sheathing for several storms before a stain appears. Repairing a cracked tile or a failed boot when you first notice it is usually far less work than replacing rotted decking later.
Related: wind & storm damage · tile roofs · roof inspections
Roof repair FAQ
The stain is in one spot. Is the leak right above it?
Often not. Water can enter the roof in one place and travel along the underlayment, deck or framing before it shows up on the ceiling. A roofer traces it back from the stain and checks the penetrations and valleys uphill of it.
Can a roof be repaired instead of replaced?
Often, yes, if the damage is localized and the rest of the roof has life left. If leaks keep popping up in different places, or the underlayment or shingles are worn out across the whole roof, a roofer may recommend replacement instead.
Can I patch it myself with roof cement?
A dab of sealant can buy time, but it can also hide the real problem and make a proper repair harder. Walking on tile can crack more tiles. If you go up at all, use proper fall protection, or leave it to a pro.