A deteriorating chimney may be the source of interior leaks and moisture.

Since most people don’t spend a lot of time on their roof, the first time they may notice a problem is on interior walls and ceilings. When chimney brick and mortar deteriorates, water is able to penetrate. Leaks eventually moisten interior walls. Here are some of the places you might first notice a problem.

1)      Moisture on the ceiling around a fireplace

2)      Moisture at the base of the fireplace or basement

3)      Moisture on plaster walls on the side of a chimney

Moisture enters the chimney through cracked chimney caps, porous brick, deteriorated mortar joints and improperly designed and installed roof flashings. Condensation can sometimes collect in cracked or separated flue tiles, blocked flues and chimney caps.

A Hinsdale client recently discovered a leak when the paint started to peel on the wall on the side of the fireplace. The wall also felt damp. It turned out the chimney crown had cracked, allowing moisture to penetrate the brick. Shamrock Tuckpointing replaced the chimney crown, tuckpointed the chimney and also applied a waterproof sealant to the brick, as an added measure of protection.

Every year or two, it’s a good idea to inspect your brick chimney for evidence of moisture damage. Look for signs of moisture damage such as efflorescent salt stains, deteriorated mortar joints, spalled bricks, or cracked chimney caps. Check the angle of the chimney to see if it might be leaning, indicating a structural issue. Flashings should fit tightly against the chimney.

Early detection of potential issues will keep you from more expensive repairs in the future. If you suspect a leaking brick chimney, contact a professional masonry contractor to see if chimney repair is needed.

John Gallagher is the owner of Shamrock Tuckpointing, based in Alsip, Ill..  The company serves the Chicago metro area from the South Suburbs to Northwest Suburbs, Western Suburbs, North Suburbs, O’Hare area, North Suburban Lake County, East-West Corridor/DuPage County, and Northwest Indiana.