5 Ways Heavy Rains Damage Roofs

When most people think of storm damage, their concerns are primarily about hail and wind. Heavy rains, especially if they occur often, can result in just as much damage as those more immediately harrowing storms. Knowing how heavy rain damages a roof helps you know what to look for after the storms pass. 

1. Pooling Water

Rain can come down faster than it will drain from the roof. This leads to water pooling on the roof surface. Low slope roofs and those roofs with complicated designs featuring multiple valleys are most prone to pooling water. The slow draining water may then seep beneath the shingles and cause damage to the roof sheathing below, or worse, leak into the attic.

2. Sealant Failure

Sealant is used on multiple parts of the roof, primarily around vent flashing and other roof penetrations. It may also be used to make roof valleys more waterproof. Constant moisture exposure, which can happen during a season of heavy rains, can cause the sealant to prematurely weather until it begins to crack or peel. Water will then seep under the shingles or flashing at the point of sealant failure.

3. Rotting Eaves

Heavy rain can result in a flow rate off the roof edge that is much greater than your gutters can safely route away. Instead, water overflows the gutters and runs onto the eaves. If you have wooden eaves, there is a chance that prolonged moisture damage can lead to wood rot. The chance is greater if there is damage or aged paint on the eaves. A roofer will need to replace the rotting eaves before the damage affects the sheathing and other roof components.

4. Ice Dams

Heavy rains in late fall, early spring, and winter can lead to ice dams. The heavy flow of water backs up at the gutters, which can cause it to backflow beneath the shingles. If temperatures drop, the water freezes and expands. This lifts the shingles and results in an ice dam that creates more backflow issues. As the ice melts beneath the shingles, it will then leak into the home and a repair will be necessary.

5. Moss Buildup

Moss won't result from a single heavy rain even, but if you have seasonally heavy rains then moss may overtake the roof during the wet season. The main concern with moss is that it traps moisture, which will eventually saturate the roof and cause the shingles to age and begin to leak prematurely.

Contact a roof storm damage repair service if you suspect heavy rain is causing your roof to degrade.