All chimneys need maintenance and summer is the best time to do these tasks before the busy fall season arrives. Many problems can be avoided or mitigated before they become serious and expensive repair issues. Here are some tips from experts at the Midwest Chimney Safety Council about how to identify common problems, and suggestions for solutions.
Spalling bricks on chimney
Problem: Bricks or stones spalling or flaking off. Masonry chimney exteriors take a beating during the winter months by exposure to harsh weather, and can have noticeable damage by springtime. Rain year-round does not help the issue. If you see spalling or flaking bricks, or find pieces of brick on your roof or yard, this is an indication that the bricks have been saturated with water, and subjected to freeze/thaw cycles. Soft type bricks, which are commonly used by masons are more susceptible to water penetration than hard type bricks and may show significant damage in just a few years. Deteriorated or missing mortar joints also need to be addressed in order to prevent water from entering the inside of the chimney where it can cause further damage.
Solution: Remove badly damaged bricks and replace with new similar color and style bricks. Grind out bad mortar joints and point or “tuckpoint” with new matching color mortar and joint style. Then apply a special masonry water repellant sealer to the entire chimney, being careful not to get the solution on the roof, windows, or cars. It is best to hire an expert for the job who knows the proper materials and methods to use.
Problem: Sooty smell or bad odors coming from the fireplace.
Solution: Have the chimney cleaned by a professional chimney sweep to remove smelly, flammable creosote. Spring is the best time to get a sweep out quickly. Note: if you suspect that there are dead animals in the chimney call an animal removal expert first, and then call a chimney sweep. The sweep may also offer a deodorizer for the chimney.
Problem: Leaking inside the house around the chimney, or walls and ceilings near the chimney.
Solution: This is usually a flashing problem that can be corrected by installing new J and Counter flashing around the chimney and/or sealing it with silicone, however, sometimes cracks or holes in mortar can cause leaking as well.
Rusted chase top
Problem: Rusting, metal crown on prefabricated chimney, water inside the chimney chase or firebox rusting.
Solution: Have a new metal crown made with breaks in the corners to the center to encourage water runoff. These are all custom-made and measurements must be taken first. Make sure the proper flashing and ran cap are installed. Do not use different manufacturer parts – to do so can be a fire hazard.
Problem: Masonry chimney crowns crack, deteriorate, and lift from the top row of bricks due to exposure to weather, expansion from heat, or improper installation. The cement crown is the primary part of the chimney that keeps water out of the flue, firebox, and damper where moisture can cause mortar joints to deteriorate and dampers and metal fireboxes to rust.
Solution: For bad cracks and deterioration, or a lifted crown (if a gap exists between the crown and top row of bricks) have the entire crown removed and rebuilt. A crown with a 2” drip edge or “poured” crown offers more protection than the commonly used sloped crown. For minor cracks or deterioration, the crown can be coated with an elastomeric compound called Crown Seal or Crown Coat.