How to locate and prevent a disastrous ceiling leak

 Ceiling leaks can be a hazardous breeding ground for moulds and termites.  Should you suspect a leak, make a hole in the wet part of the ceiling. This will make the damaged area minimal so that your repair will not be as extensive.

See some tips on how to locate your leak before your plaster repair takes place.

1. Roof Leaks determine if the leak occurs only during bad weather or is a continual problem rain or shine. If the leak dries out between storms, this is a good indication that the leak starts somewhere on the roof. If the leak is consistent when it rains or shines, the leak probably comes from a plumbing water supply line.
2. Examine the water leaking from the ceiling. If the water appears fresh, there's a good chance it comes from a leaking plumbing line or fixture. If the water is dirty or stains the ceiling, the source might be a leak in the roof.
3. Gain access to the attic and, with a flashlight, find the place where the ceiling is wet between roof joists. You will need to remove any insulation in the way of the leak. If there is a plumbing line near the leak, such as the supply line for a swamp cooler, check the line for leaks or moisture.
4. Look up at the ceiling while in the attic and note any spots where light shines through. Insert a plastic straw through the hole. This will help you find and repair the hole from atop the roof.
5. Inspect the inside of the attic ceiling for water stains or trails. Follow the water trail or stain to its source. Make note of the area if there are no visible holes, as water might be getting under roof flashing and causing the leak.
6. Inspect the roof's exterior. You may need a roofer or plumber for this. 
7. Start at the top of the roof and work down. Check valley flashing, gaskets around plumbing vents and utility entrances. Inspect flashing around chimneys, dormer vents or other roof protuberances. Look for any shingles in need of repair.
8. Review all areas of the roof where two different materials meet, such as between siding, shingles or flashing. Look for corroded or damaged materials as sources of ceiling leaks.
9. Check gutters and downspouts for clogs. Backed up drainage water can get under flashing and cause a ceiling to leak.