By Omer Okic, owner of Ultimate Exteriors · 28 years on Des Moines homesOriginally published April 2022 · Updated November 2026
Most roof leaks start at a cracked pipe boot, loose flashing, a valley or a popped nail, not in the middle of the shingles. Finding the real source matters, because the stain on your ceiling is often several feet away from it.
- Cracked rubber pipe boots are the most common leak we fix
- Flashing at walls, chimneys and skylights loosens over time
- Valleys and clogged gutters back water up under shingles
- Popped or crooked nails let water in around them
A roof leak can turn into an expensive problem fast: wet insulation, stained drywall and, left long enough, rotted decking and mold. The good news is that most leaks come from a few predictable places, and most can be repaired without a new roof.
Pipe boot failure
A pipe boot is the rubber-and-metal collar that seals around plumbing vent pipes coming through the roof. Sun and Iowa's freeze-thaw cycles crack the rubber over time, usually well before the shingles wear out. Water runs down the pipe and into the attic. The fix: replace the boot and re-seal the shingles around it.
Loose or failed flashing
Flashing is the metal that seals the joints where the roof meets a wall, chimney, skylight or dormer. When it loosens, rusts or was never installed right, water gets in behind it. The fix: re-secure or replace the flashing and seal it properly, not just smear tar over the gap.
Valleys and clogged gutters
Valleys carry more water than any other part of the roof. If a valley ends near a clogged gutter, or there's no proper flashing where the valley meets a wall, water backs up under the shingles. In winter, ice dams do the same thing at the eaves. The fix: clear the gutter, repair the valley and add ice and water barrier where it's missing.
Poorly driven or popped nails
Nails driven crooked, too high or not all the way in leave room for water. Over time, freeze-thaw can push nails up under the shingle above them. The fix: lift the shingle, remove or reset the nail, seal the hole and replace the shingle if it's damaged.
Missing or damaged shingles
Wind and hail can tear off or crack shingles and expose the underlayment. A few missing shingles is a simple repair; widespread hail damage may be an insurance claim. See our hail damage guide.
Find the real source
Water travels along rafters and decking before it drips, so the stain on your ceiling is often not under the leak. A good roofer checks the attic and the roof to find where water is actually getting in. Text a photo of the problem to (515) 419-7459 and we can often tell you if it's a simple repair before we come out.
Quick answers
What is the most common cause of roof leaks?
Cracked rubber pipe boots around plumbing vents are one of the most common, followed by loose flashing at walls, chimneys and skylights.
Can a roof leak be repaired without replacing the roof?
Usually, yes. Most leaks come from a specific spot like a boot, flashing or a few damaged shingles, and can be repaired on their own.