Instructions

1

Climb a ladder to the roof on a dry day. Walk the surface of the roof. Look for any obvious signs of a leak, such as a low spot surrounded by a dirt ring. This is typically a sign of pooling water; if the roofing material is damaged, a puddle can often cause a leak.
2

Check any and all roof flashing for peeling or holes. One of the most common sources of roof leaks is flashing. Flashing is typically installed anywhere the roof transitions, such as around pipes or at the roof's edge.
3

Take a look at any seams. Any areas where materials overlap, such as the spot where two shingles or pieces of tin meet, is a potential leak. Examine the area for holes or pulled-up roofing material.
4

Spray the area where the roof is most likely leaking with a hose. Go inside the house to the spot where the ceiling is leaking and wait to see if you produced a leak. It typically takes at least ten minutes for the moisture from a roof leak to reach the leaking spot inside the house, so give it time. If the test spot is not causing your leak, continue testing spots until you find the source of the leak. If you have to spray much of the roof, this can take hours. Alternatively, you can hire a professional to evaluate the source.