Finding and Repairing Leaks in Roofs
Causes of Leaks
1. Defective flashing may be detected by wet spots near a chimney or outside
wall. On sloping roof valleys and at junctions of dormers and the roof, look
for corroded, loose, or displaced flashing. Defective flashing often occurs
around dormers and plumbing vent pipes.
2. On flat roofs, check for choked or clogged downspouts. Accumulated water on
the roof above the flashing may cause leaks.
3. Roofing, especially wood or composition shingles, usually deteriorates first
on southern exposures. Check southern slopes for cracking or deterioration.
4. Wet spots on plain roofs are usually caused by missing shingles or holes in
roofing. To find holes, look for light coming through places in unsealed
attics. Stick a straw through the hole to mark the spot on the outside.
Making Temporary Repairs of Leaks
Methods of repair will depend on the kind of roofing and the nature and extent
of the leak.
5. Missing shingles: Replace missing shingles with similar shingles or pieces
of rust-resistant metal. In an emergency you can use metal cut from a tin can.
6. Paint the metal on both sides and slip it under the upper layer of shingles.
Be careful not to dislodge or loosen good shingles.
7. Cut out old nails with a long thin cold chisel.
8. Cover exposed nails with roofer’s cement.
Holes
9. Patch small holes with metal screws. Use neoprene washers in low places.
10. Repair large holes by using a metal sheet or heavy plastic or canvas and
elastic roofer's cement. Apply cement carefully over the patch. Keep the
plastic or canvas tight and cover with roofer's cement to keep from sagging
into the hole.
Cracks
11. Brush on two coats of roof coating.
12. Place a heavy cloth, plastic or light canvas over the cracked area,
extending the cloth approximately 6 inches beyond the cracked area. Use a
roofing brush to smooth out the material and brush on two thin coats of roof
coating. Keep cloth smooth while brushing.
Caution: Do not walk on any patched section.