You can’t always tell by looking at it that your chimney isn’t safe and sound. There are, however, some visible signs that repair may be needed. Since chimney safety is equivalent to safety from obvious fire hazards, every homeowner with a chimney should become familiar with telltale signs of damage.
1-Damaged Mortar Joints
It may require a rooftop vantage point to spot, but damaged mortar joints between chimney masonry is an issue which should be hastily repaired. Failing mortar joints can mean accelerated damage to the chimney, since the condition exposes the bricks to greater amounts of moisture. When water gets into small cracks in the masonry, they can turn into large cracks, particularly as a result of freezing and thawing. Ultimately, if the problem isn’t addressed, the chimney could collapse.
2-Rusted Damper or Firebox
Signs of moisture in a chimney or fireplace are red flags that the chimney isn’t operating the way it should. Rust is one clue that there is too much moisture, and you may see rust in the firebox or on the damper. You’ll know to take a close look at the damper if it becomes difficult to operate or if it isn’t sealing properly.
Moisture in the chimney which causes rusting can create numerous problems, including causing flue tiles to crack. A cracked or deteriorated flue lining is highly dangerous, since it could allow too much heat into vulnerable areas and cause a house fire.
Spalling occurs when water enters brick, natural stone, or concrete and forces the surface of the masonry to pop out, peel off, or flake off. Sometimes salt also pushes outward from the inside and causes spalling. It’s fairly simple to spot spalling, since bits of masonry fall from the chimney. The ultimate outcome of failing to repair spalling masonry is continued crumbling and eventual destruction of the structure.
4-Shaling Flue Tiles
Thin slices of chimney tile can begin to pile up at the bottom of the chimney, if the liner is damaged. Cracked and shaling flue tiles are signs of a serious condition which, if not resolved, could result in a house fire. The flue lining of a chimney must be intact in order to safely use a fireplace. Many people today are switching to stainless steel liners, which usually carry lifetime warranties.
While shaling flue tiles can become evident, identifying cracked flue liners often requires an inspection by a professional chimney sweep who uses a special camera. The camera can spotlight potential problems in the flue which are difficult if not impossible to see otherwise.
5-Cracked Chimney Crown
Another problem that requires a visit to the rooftop to spot is a damaged chimney crown. It’s important for the crown to be in good condition, since it provides a first line of defense against outdoor elements. When the crown is cracked, water gets in and freezes and thaws, causing larger cracks. A damaged chimney crown allows moisture to seep between the chimney and the liner as well as into the chimney, which can cause shaling and spalling.
A great preventative measure against this type of damage is to weatherproof the chimney crown and, while you’re at it, the chimney itself.
If you notice that the wallpaper is damaged in areas near the chimney, it could be because of excess moisture in the chimney. Whether the moisture problem is caused by above-named conditions or others that are less obvious, it should be repaired without delay.
It’s smart to be alert to problems with your chimney, but it’s even better to trust a professional chimney sweep to do a thorough cleaning and inspection annually. Schedule your annual cleaning in the spring so that there is plenty of time to make repairs before the return of chilly weather.
Northeastern Chimney, Inc.
formerly Nayaug Chimney Services, LLC
37 Cody Street, West Hartford, CT 06110