Common Causes of Roof Leaks and How to Fix Them

If you have a roof leak, the first step is to find it. Look for water stains on the ceiling or walls and follow them to find the source of the leak.

Also check the attic and crawl space for water damage. Most leaks occur around pipes, vents, chimneys, dormers, and other construction that projects through the roof.

1. Damaged Flashing

Flashing is a thin strip of metal that connects the seams of roof installations like chimneys, vents and skylights. It is a layer of thin metal that is installed underneath shingles and around the roof joints to create a water-resistant barrier. It creates a barrier to keep water out, but it can crack and break over time due to inclement weather, physical damage and normal wear and tear. If your roof flashing becomes damaged, it can allow water to seep through the shingles and into the attic, where it can cause mold and other problems. If the flashing becomes cracked, it gives rainwater a direct path into your home. This can happen due to physical damage from the elements, age, or improper installation.

Chimney leaks often occur when the flashing surrounding the chimney becomes damaged or rusted. The area surrounding roof vents can also experience leaks when the seal between the vent pipe and the roof becomes compromised. You may notice brown water stains on the ceiling near the vent or a musty odor in your attic.

One of the most common causes of leaks is cracked or broken flashing, especially around items that penetrate the roof such as pipes, dormers and vents. Leaks can also occur in the roof valleys where two planes of the roof meet, and these areas are particularly vulnerable to moisture and debris.

A common sign of flashing damage is the appearance of stains on the ceiling or walls. These are caused by water infiltrating the living space, and can lead to mold and mildew buildup as well as rot in the joists and timber framing of the building.

Cracked flashing can be a serious issue that requires professional help. If you see any of these signs, call a roofing repair expert immediately to inspect your roof for damaged flashing. You can try a quick fix by applying flashing tape, which has a self-adhesive backing and is designed to stick to cracks and fill gaps. This is a temporary solution, though, and should be replaced with new flashing soon.

2. Clogged Gutters

Gutters are designed to channel rainwater away from your home, but they can become clogged with leaves, twigs and branches. When this happens, water can spill over the gutters and pool around your foundation, causing erosion and weakening walls. Over time, this can lead to a sagging foundation and even cracks in your basement wall.

A clogged gutter can also damage the fascia board, which is located along the lower edges of your roof. If the water overflows and pools near the fascia board, it can cause rot and lead to a leaky roof.

A leaking gutter can be difficult to locate, but it’s important to find the source of the problem as soon as possible. Use a bright flashlight to walk along the framing of your roof, looking for signs of moisture or dampness. You should also look for any areas where light is coming in through the ceiling. This can be a sign of a leaking skylight or vent boot, which may need to be replaced. You can patch these leaks temporarily if the skylight is not broken, but it’s best to call a professional for more extensive repairs.

3. Damaged Shingles

Damaged shingles are one of the most common causes of roof leaks. When a shingle is damaged, it creates a gap that allows water to seep underneath and cause damage to the roof deck and fascia boards. This can lead to rot and water intrusion into the home. To prevent shingle damage, regularly inspect your roof and repair any loose or damaged shingles.

A nail that backs out through a shingle is another common cause of leaks. This can happen when a roofing nail isn’t driven in far enough or is driven in sideways. When it rains, the water can catch the nail head and push it upward through the shingle and into your ceiling.

To repair a leaking shingle, first remove the surrounding shingles to expose the nails. Slide a pry bar under the row of shingles directly above the damaged area and slowly loosen them. Carefully lift up each shingle to expose the nails, then remove them and discard them. Once the nails are removed, use a utility knife to cut off any exposed shingle flashing.

4. Dirty Gutters

Gutters are important for directing rainwater away from the roof, but they can become clogged with leaves, twigs, and other debris. When this happens, water can build up and pool on the roof, resulting in leaks.

Clogged gutters can also lead to pest infestations. Stagnant water and the moist, softened debris in clogged gutters can attract mosquitoes and other insects that can carry diseases like West Nile Virus and Zika.

A clogged gutter can exacerbate ice dams, which form when heat from inside the home escapes into the attic and warms the snow on the roof. The melting snow then refreezes at the edge of the roof, creating a ridge of ice that blocks the flow of water and causes damage to the gutters and fascia.

A clogged gutter can also cause water to seep under shingles and into the structure of the home, leading to rotting fascia boards and water infiltration into the attic. To avoid this, make sure your gutters are clean and free of debris regularly. Also, be sure to have proper ventilation in rooms with high moisture content (like bathrooms and sunrooms). If there isn’t adequate venting, humidity can build up, which may cause water damage.