Masonry fireplaces, whether wood-burning or gas, are cozy features that represent the epitome of home for many owners. Yet cracks in brick, or in the masonry joints between bricks, are early warning signs that your chimney is on the road to ruin. Patching cracks in your brick chimney can save you thousands of dollars worth of repairs later on, as well as keep you and your family safe by reducing the possibility of chimney fires.
Small cracks in the summer can become surprisingly large cracks by next spring. Letting those larger cracks in the outer brick go unattended will deepen the penetrating effect of rain, snow, and ice. Then, the water begins to work its way down, sometimes between the outer brick and the flashing, sometimes farther inside, between the outer brick and the flue.
Left unchecked, these tiny events can accumulate and result in disaster for roof systems and interior ceilings, insulation, wall studs, and even floors.
Repair Cracks to Prevent Chimney Fires
Even worse, cracks in a brick chimney that continue from the flue to the exterior are one cause behind a terrifying, devastating phenomenon: a chimney fire. Chimney fires can ignite instantly—those who have experienced them describe them as an explosion followed by a sound similar to a freight train. Once a chimney fire has started, only the fire department can stop it since it must be extinguished from the top-down.
The good news is that cracks in a chimney’s brick, mortar, crown, and cap are very easy for a do-it-yourselfer to fix with only a few simple tools and materials. Pick a warm, dry day for this project, as some of the materials need a few hours of curing time.
In most communities, minor brick chimney repair that does not involve replacing any elements of the chimney should not require a permit. If you are removing and replacing bricks in your chimney, check with your local permitting office. In some areas, this kind of work requires that you apply for a permit and have the work inspected once you complete it.
Brick chimney repair is dependent on seasons and weather. Do not apply mortar when temperatures are below 40 degrees Fahrenheit. If you are applying the mortar in warm weather but expect temperatures to drop below freezing within 24 hours, do not apply the mortar. Instead, wait until the temperatures are favorable.
Any time you are working on a roof there is the potential for falls and serious injury, and the higher the roof or the steeper the pitch of the roof, the greater the danger will be. If you choose to do your own chimney repair, make sure to work on a dry day, and wear shoes or boots with firm-grip soles. Never work on a roof that is damp.
Consider using a safety harness, also called a fall-arresting harness, whenever working on a roof—especially if the roof is very steep or very high. The equipment includes a metal ridge anchor that is attached to the peak of the house, a body harness that fits around your back and hips, and a rope with an automatic locking mechanism that prevents you from falling a long distance. Fall-arresting harnesses can be rented at home improvement centers and tool-rental outlets.
Work slowly and carefully when making chimney repairs. Impatience and hurried work invite accidents.
Source: The Spruce