Leaks: The Uninvited Houseguests
No one wakes up hoping for a roof leak. They’re messy, stressful, and often sneak up on you with that telltale brown stain or dripping ceiling. But before you panic, it helps to understand what causes roof leaks in the first place—and which ones are most common.
Knowing the source can help you catch problems early (before they become disasters), and maybe even prevent them altogether. Let’s dig into the usual suspects.
Damaged or Missing Shingles
Shingles are your roof’s first line of defense against the elements. When they’re cracked, curled, or missing altogether—usually thanks to wind, hail, or age—water can seep in underneath and cause a leak.
These issues are especially common after major weather events. Wind can lift and displace shingles, breaking the waterproof seal and exposing your roof to water intrusion.
Regular visual inspections, especially after storms, can help spot trouble before it leads to interior damage.
Cracked Flashing
Flashing is the thin metal installed around chimneys, vents, skylights, and roof edges to seal joints. Over time, flashing can corrode, lift, or crack—especially if it was poorly installed. Once compromised, it’s a prime path for water to slip in.
Tar-based flashing cement, a common older method, is especially vulnerable to drying and cracking. Today, most professionals use more durable metal flashing secured with roof sealant or rubberized adhesives.
Clogged Gutters
Gutters that are full of leaves and debris can’t drain water effectively. Instead, water pools and backs up onto the roof. Over time, that extra moisture can work its way under shingles and into your attic or ceiling.
Keeping your gutters clean—or installing guards—helps ensure water flows freely off your roof. It’s one of the simplest ways to avoid leaks.
Poorly Sealed Roof Valleys
The valleys—where two roof slopes meet—are particularly vulnerable to leaks. Water naturally flows through them, so if the sealing materials degrade or weren’t applied properly, leaks often follow.
This is especially common in older roofs or areas where heavy snow sits and melts slowly. Valleys should be lined with a waterproof membrane and carefully shingled to direct water flow.
Ice Dams
In colder climates, snow that melts and refreezes near the roof edge can create a dam. This dam traps water behind it, forcing it up under the shingles and into your home.
Proper insulation and ventilation are your best defenses. Good attic ventilation keeps roof temperatures more consistent, preventing the freeze-melt cycle that causes ice dams.
Skylight Leaks
Skylights are beautiful, but they also cut a hole in your roof—and if not installed or sealed properly, they’re a common leak source. Look for signs of moisture or mold around the inside edges.
Leaks can occur around the flashing, frame, or from cracked glass. Condensation buildup may also be a sign of inadequate insulation around the skylight opening.
Cracked or Worn Vent Booting
Vent boots are rubber or metal pieces that seal around plumbing vents. Like flashing, they can crack or deteriorate over time, allowing water to seep through. This often leads to isolated ceiling spots in bathrooms or laundry rooms.
Rubber boots can become brittle with sun exposure, especially in older homes. Replacing them is relatively simple and cost-effective.
Aging Roof Materials
Sometimes the cause is simply time. Roofs wear out. Shingles lose their granules, underlayment breaks down, nails loosen. Once your roof hits the 15–25 year mark (depending on materials), leaks become more common, even without major storm damage.
If you’ve recently noticed increased granule loss in your gutters or a general “worn” appearance, it might be time to start planning a replacement.
Need Assistance with Your Claim?
Brody Allen Exteriors can help guide you through the process and ensure your roof is repaired to the highest standards. Many of your neighbors have successfully navigated their insurance claims with our expert assistance.
Improper Installation or Past Repairs
A roof is only as good as the team that installed it. Bad nailing patterns, shortcuts on flashing, or low-quality sealants can all lead to problems—sometimes just a few years after installation.
Even repairs done with good intentions can create issues if they aren’t matched to the existing system. For example, layering new shingles over old ones (a common practice in the past) can trap moisture and lead to long-term damage.
Chimneys and Wall Junctions
Chimneys and vertical wall intersections require careful flashing work. If that flashing is damaged or missing, water can run right down into your home’s framing. Pay attention to musty smells or stains near those areas.
Water often sneaks in through hairline cracks in masonry or poorly sealed bricks. Tuckpointing and sealing, along with proper flashing, keep these joints watertight.
Less Common But Still Notable Causes
- Punctures from falling branches
- Animal damage (like raccoons or squirrels)
- Satellite dishes or roof-mounted hardware with poor seals
What to Do if You Suspect a Leak
- Check your attic for water stains, wet insulation, or moldy smells.
- Look for visible damage on your roof—shingles out of place, rusted flashing, or pooling water.
- Watch for interior signs like ceiling spots, bubbling paint, or musty odors.
- Call a roofing professional to inspect the area and confirm the source.
The sooner you catch a leak, the easier (and cheaper) it is to fix. Waiting often turns a small patch job into a major interior repair. If you want to know what to look for when checking for signs of damage, our Learning Center has guides on roof inspections, storm damage, and more.
Final Thoughts
Roof leaks can start small, but they never stay small for long. Understanding the common causes helps you stay proactive and avoid costly surprises.
Need help figuring out what’s causing your roof leak—or just want peace of mind before the next storm? Contact Brody Allen Exteriors for a professional inspection. We’ll find the problem and help you fix it right the first time.
Stephen Maassen
MISSOURI'S BEST
Roofing Professionals You Can Trust
When you choose Brody Allen Exteriors, you're choosing a team that's dedicated to protecting Missouri homes. We live and work in this community, and we're here to ensure your roof is strong, durable, and built to last.
