You have the power to address leaks yourself—no prior experience is required. We guide you through identifying and resolving the most prevalent types of roof leaks. Many leaks can be fixed in just minutes.
Leaky Roof Overview
If you’re noticing water stains stretching across ceilings or running down walls, chances are your roof is leaking. Pinpointing the source of the leak can be challenging, but repairing it is typically straightforward. We’ll share some easy techniques for identifying and fixing most common types of roof leaks. However, if you reside in the Snow Belt and experience leaks only on warm or sunny days during winter, you might be dealing with ice dams, which we won’t cover in this story. For more information on preventing ice dams, refer to this article.
It’s crucial to address a leaky roof promptly, even if it doesn’t seem like a significant issue or if you’re planning to replace the roof soon. Over time, even minor leaks can cause significant problems such as mold growth, rotted framing and sheathing, compromised insulation, and damaged ceilings. For instance, the flashing leak that resulted in an expensive repair could have been identified early from ceiling stains persisting for over two years. Had the homeowner addressed it promptly, the damage and subsequent repairs would have been minimal.
How to Find Roof Leaks
When attempting to locate a leak, begin by inspecting the roof uphill from the stains. Your initial focus should be on any roof penetrations. These are the most common sources of leaks. In fact, leaks seldom occur in areas of uninterrupted shingles, even on older roofs. Penetrations may include plumbing and roof vents, chimneys, dormers, or any other structure protruding through the roof. They might be located several feet above the leak or to its right or left.
If you have attic access, the most straightforward method to pinpoint a leak is to venture up there with a flashlight and search for evidence such as water stains, black marks, or mold. However, if attic access is limited or if you have a vaulted ceiling, you’ll need to climb onto the roof and inspect the suspect areas directly.
A Trick for Finding Difficult Leaks
If you’re struggling to locate a leak, recruit a helper and head up onto the roof with a garden hose. Begin at a low point, saturating the area just above where the leak manifests inside the house. Be methodical in isolating different areas as you run the hose. For instance, start by soaking the downhill side of a chimney, then each side, and finally the top on both sides. Instruct your helper to remain indoors, ready to alert you when a drip becomes visible. Allow the hose to run for several minutes in each area before shifting it slightly up the roof. Your helper should call out when a drip emerges. This process may take more than an hour, so remain patient and refrain from moving the hose prematurely. Consider treating your helper to dinner for their assistance.
If running water fails to pinpoint the exact location of the leak, don’t hesitate to take action. Begin by removing shingles in the suspected area. With the shingles removed, you’ll uncover evidence of the leak, enabling you to trace it directly to its source. Look for discolored felt paper or signs of water staining or wood rot in the vicinity of the leaky roof.
Solution for a Small Leak
Some roof leaks can be elusive, with water appearing at a ceiling spot distant from the actual source. If your ceiling features a plastic vapor barrier between the drywall and attic insulation, gently move aside the insulation and inspect the plastic for any signs of flow stains. Water often travels to openings in the vapor barrier, such as around ceiling light fixtures.
If you don’t notice any evident flow marks and the stain is relatively small, examine the underside of the roof for “shiners.” Shiners are nails that missed the framing member, typically occurring when the carpenter nailed the roof sheathing to the rafters. Moisture from the rooms below can escape into the cold attic and condense on these cold nails. On a cold night, you may observe these nails appearing white due to frost accumulation. As the attic warms during the day, the frost melts and drips, only to frost up again at night. The solution is to simply clip the nail using side-cutting pliers.
Fix Plumbing Vent Boots
Plumbing vent boots come in various materials, including all-plastic, plastic and metal, or two-piece metal units. Begin by inspecting plastic bases for any cracks and metal bases for broken seams. Next, examine the rubber boot surrounding the pipe; it may be rotted or torn, allowing water to penetrate into the house along the pipe. If you detect any of these issues, it’s advisable to purchase a new vent boot to replace the old one.
However, if the nails securing the base are missing or have pulled free, and the boot is in good condition, consider replacing them with rubber-washered screws commonly used for metal roofing systems. These screws can be found at any home center alongside other screws. You’ll need to carefully work neighboring shingles free on both sides for access. If you don’t have spare shingles, take care when removing them so they can be reused. Utilize a flat bar to separate the sealant between the layers, then slide the flat bar under the nail heads to remove the nails.
How to Fix Roof Vents
Inspect plastic roof vents for cracked housings and metal ones for broken seams. While it may be tempting to apply caulk as a quick fix, this solution is unlikely to last. In most cases, the only effective remedy is to replace the damaged vents. Additionally, check for pulled or missing nails at the base’s bottom edge, and consider replacing them with rubber-washered screws.
To remove the vent, you can typically extract nails under the shingles on both sides without damaging them. There will likely be nails across the top of the vent as well, which you can often loosen without disturbing the shingles. Secure the bottom of the vent with rubber-washered screws. Apply a bead of caulk beneath the shingles on both sides of the vent to secure them in place and create a water barrier. This method is much simpler than renailing the shingles.
While addressing the vent, take the opportunity to familiarize yourself with the concept of a birdsmouth cut, which is used to create a joint for fixing rafters and joists to wall plates.
Fix Walls and Dormers
Water infiltration isn’t always limited to the shingled surface. Oftentimes, wind-driven rain can enter from above the roof, particularly around windows, between corner boards and siding, and through cracks and knotholes in siding. Dormer walls present numerous points where water can trickle down and find its way into the roof.
Caulk in these areas may be aged, cracked, or missing altogether, allowing water to penetrate cracks and seep behind flashing, leading to interior leaks. Even seemingly intact caulk may fail to seal properly against adjoining surfaces. Use a putty knife to inspect and ensure proper sealing. Remove any suspect caulk and replace it with a high-quality alternative.
Additionally, examine the siding above the step flashing. Replace any cracked, rotted, or missing siding, ensuring the new piece overlaps the step flashing by at least 2 inches. If the leak persists, detach the corner boards and inspect the overlapping flashing at the corner, where old, hardened caulk may be present at the inside corner overlap.
Complex Roof Problem
This roof exhibits leaks during the snowy periods of winter and storms in the summer, likely due to inadequate flashing. Waterproofing the soffit-to-roof junction poses a significant challenge. In the provided photo, remnants of an ice dam are still visible. An ice dam forms when snow melts and freezes upon hitting the colder roof edges. Over time, water accumulates behind the dam, seeping under the shingles and soffit until it finds a route through the roof.
Addressing this issue starts with ensuring proper flashing, as this not only prevents rain leaks but may also mitigate leaks caused by ice dams. Begin by carefully removing the shingles down to the wood sheathing and sliding a strip of adhesive ice-and-water barrier beneath the soffit/main roof joint. Depending on the roof configuration, you may need to cut a slot to insert the barrier adequately. Ensure it overlaps another piece of ice-and-water barrier below, extending down to the roof edge to cover the most vulnerable areas.
Subsequently, reshingle the area, inserting metal step flashing behind the fascia board. The valley flashing, laid over the joint where the two roofs meet, should overlap the step flashing by at least 2 inches. If leaks persist due to ice dams, consider installing roof edge heating cables, available at local hardware stores or home centers.
While improved attic insulation and ventilation typically prevent ice dams, they may not fully address the complexities of this leaky roof situation.
Fix Step Flashing
Step flashing is employed along the juncture of walls and the roof to redirect water over the shingle downhill from each section. However, if the flashing corrodes or a segment becomes dislodged, water can easily bypass it, leading to water infiltration into the house. Rusted or damaged flashing must be promptly replaced. This entails removing the affected shingles, loosening siding as necessary, and then removing and installing new step flashing. While it may sound straightforward, occasionally a roofer may overlook nailing a piece of flashing in place, causing it to slip down and expose the wall.
Don’t Count on Caulk!
Using caulk or roof cement rarely provides a lasting solution for a leaky roof. Whenever feasible, it’s best to pursue a “mechanical” fix for roof leaks. This involves replacing or repairing existing flashing rather than relying on sealants as leak stoppers. Caulk should only be utilized for very minor holes or when flashing isn’t a viable option for sealing a leak.
Fix Small Holes
Small holes in shingles can be deceptive, as they can lead to rot, roof leaks, and other damage over time without immediate notice. These holes may result from previous satellite dish or antenna mounting brackets, or various other sources. Exposed or misplaced roofing repair nails should be removed, and the resulting holes patched promptly. While small holes may seem easy to remedy, the solution is not to simply apply caulk. Instead, addressing this issue involves using flashing to seal the holes effectively. Liquid flashing can assist in sealing recessed windows.
Leaks Around Brick Chimneys
Numerous issues can arise around brick chimneys, too many to address fully in this story. Flashing surrounding chimneys, particularly if made of galvanized steel, can rust through, particularly at the 90-degree bend at the base. A relatively quick but durable solution involves sliding new flashing beneath the old, rusted material, ensuring any seeping water is redirected. However, the optimal solution is to cut a saw kerf into the mortar and install new flashing for a more comprehensive repair.