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2018 National Home Improvement Estimator, All Rights Reserved Page 117

Chapter 7, Roofing and Flashing

Damage from a leaky roof is usually obvious. However, the precise source of the leak won’t always be
clear. The hole in the roof is seldom directly above the drip stains on the ceiling. Water gets through the
roof surface and runs along the top of sheathing until it finds a panel edge. Then it may run along a rafter
or the underside of the panel for a foot or so before dropping down to the attic where it puddles on the
vapor barrier. The puddle expands downhill, finds a seam, and then begins saturating the drywall or
plaster below. The distance between the hole in the roof and the wet spot on the ceiling can be several
feet or more.

So where do you start patching? If the attic crawl space is readily accessible, start your search in the
attic. Look for recent water stains. Once you have that information, you can go up on the roof and look
for:

• Missing shingles. Leaks are nearly certain when roof components get blown away.

• Physical damage. Foot traffic can break seals and dislodge shingles. Was anyone working on the
roof or in the attic before the last rain? Check for a tree branch that could be hitting the roof’s surface
during a high wind.

• Deteriorated caulking. Caulked joints harden with age and then fracture along the joint with
movement.

• Debris. Anything resting on a roof can collect water and speed deterioration. Debris tends to
accumulate on the high side of the roof next to penetrations such as a chimney or skylight.

• Shiners. Shiners are nails not covered by the shingle course above. If left exposed for many years,
the nails can rust out, leaving a hole in the roof.

• Broken mortar. Any gap or opening in a chimney or parapet wall offers an opening to the attic.

• Obstructed gutters. Be sure rain runoff gear is working properly. Water accumulating in a gutter can
back up over the top of the fascia, run along the soffit, and then down the wall interior.

• Open roll roofing seams. Even if you see bitumen or adhesive sticking out under a lap, the seam
may be wicking moisture to the interior. Try running a putty knife or pocketknife blade under the lap. If
the blade slides into the lap more than an inch, assume the seam needs to be resealed.