Is Roof Damage Caused by Moisture Entering From Outside of the Chimney?

Causes

• Defective building materials are a common cause of excess moisture and roof damage. According to the Agriculture Department at North Dakota State University, defective flashing can cause leaks in and around your chimney and subsequent deterioration of the roof. Flashing is a type of sheet metal used to waterproof your roof where the chimney and roof meet. Storm damage is another common cause of leaking roofs. Shingles may be torn off during a storm, exposing cracks and holes in the roof where moisture can seep in. Clogged downspouts and gutters are another common cause of moisture damage on roof tops. When clogs and blockages occur, excess water from melting snow and ice may leak in around the flashing and cause damage to the roof.

Effects

• Excess moisture can result in deterioration to your roof, which will require repair. If moisture is seeping into the ceiling due to roof damage, mold may begin to appear. Mold grows when fungal spores find a source of moisture, which fuels their growth. When mold is present, it can cause those living in the home to experience serious health problems. Mold may discolor the ceiling and walls inside your home, manifesting as a musty or foul odor.

Diagnosis

• Examine the outside of your roof for signs of loose or displaced flashing around your chimney to determine the cause of excess moisture. Search for signs of crumbling furnace cement around the chimney as this material will degrade over time and crumble. You should also inspect the roof for any missing shingles or holes that will allow moisture inside. Wet spots on your shingles may indicate moisture problems.

Solution

• Once you have identified the source of the moisture problem, you must repair the damage to your roof. Take care when working on your roof and never make any repairs during inclement weather. Avoid walking on any areas you have patched or repaired. Any damaged or missing shingles must be replaced and obvious holes and cracks filled in. Defective flashing must be replaced, which may require the services of a roofing contractor for proper installation. Remove any debris or leaves from your downspouts and gutters to keep water from backing up into them.