Reading Your Own Roof
Lesson 11. Reading a Ceiling Stain
The timing of a ceiling stain tells you more than its location does, and a good share of them turn out not to be the roof at all.
At a Glance
- When it appears matters more than where it is
- Brown ring with a dark center means it has happened repeatedly
- Stains with no rain are plumbing or condensation
- A bulging ceiling should be drained, carefully, right away
Start With When
| When It Shows Up | Most Likely Cause |
|---|---|
| During or just after heavy rain | Roof or flashing |
| Only with wind driven rain | Flashing, siding or a window above |
| In late winter and early spring | Ice damming |
| On cold days with no rain at all | Condensation in the attic |
| Any time, unrelated to weather | Plumbing, in a bathroom or kitchen above |
| In summer, near an air handler | The HVAC condensate line |
Working out which of these it is costs you nothing and it can save you calling the wrong trade entirely.
Reading the Stain Itself
- A brown ring with a darker center means it has dried and rewet many times
- A yellow tinge often means it has come through old nicotine stained plaster
- Black spots and any musty smell mean it has been damp long enough to grow mold
- A crisp edge means one event. A soft spreading edge means an active leak
- A bulge means there is standing water above it right now
If It Is Bulging
Water pooling on the top of drywall will eventually bring the ceiling down in one piece, which is dangerous and far more expensive than the leak.
- Move everything out from under it
- Put a bucket down, with a towel in it to stop splashing
- Poke one small hole in the lowest point of the bulge with a screwdriver
- Let it drain. Do not make a second hole until the first stops running
Worth knowing. That small hole is a patch. A collapsed ceiling is a room. Make the hole.
The Stain Will Come Back
Painting over a stain without fixing the cause is the most common mistake here. Ordinary paint will not seal it either. The tannins bleed straight back through in a few weeks.
Fix the water first. Then seal with a stain blocking primer. Then paint. In that order, or you will do it twice.