Five Causes Of Roof Rot

Posted on: 31 March 2020

Roofs aren't immune to rot. Most roof decking is made of plywood that is supported by wooden rafters, both materials that can rot when exposed to moisture. Even asphalt shingles can begin to break down and decay, especially if moisture gets beneath the shingles. The following are five likely causes of roof rot. By knowing what they are and how to spot them, you can prevent many rot issues before they can even begin.

1. Moss

Whether you only have a few mossy areas or your roof is a veritable carpet of green, these small plants can mean big trouble. Moss traps moisture against the roof, which can increase the chances of shingle rot. If the moss gets beneath a shingle and lifts it up, the moisture can then get into the decking and lead to interior rotting and leaks. Prompt moss removal and the installation of zinc strips on the roof can prevent problems.

2. Heavy Shade

Roofs that are beneath trees and in heavy shade take longer to dry out, so moisture damage to shingles is more likely. As the shingles begin to rot, the chances of the moisture seeping through them and into the decking also increase. Trim back trees to allow some light and air circulation to reach the roof to help minimize these concerns.

3. Aging Shingles

Putting off a necessary roof replacement for too long increases the chances of damage reaching into the decking and base materials of the roof. Signs of aging on shingles include curling, cupping, cracks, tears, and loss of granules. Replace old shingles as soon as they begin to wear out so that you can ensure moisture never makes its way into your roof's base materials.

4. Hidden Leaks

A roof can look fine from the ground but still have leaks that aren't easily seen. Take the time to look in your attic a few times each year. If you see pinpoints of light through the ceiling or find signs of moisture damage, like water stains on the ceiling or wet insulation, you need to schedule a roof inspection to find the source of the damage. Prompt repairs will prevent rotten decking and trusses.

5. Attic Humidity

Sometimes moisture problems that lead to roof rot stem from the interior of your home. Poor roof ventilation can cause the warm, humid air in your home to become trapped in the attic, effectively rotting your roof from the inside out. A roofer can check your ventilation and add more if necessary.

If you suspect rot damage on your roof, contact a roof repair contractor immediately.