Fact: even slight seismic activity can cause chimney damage. And it doesn’t take the proverbial Big One to send them tumbling onto roofs, cars, decks and/or people. Chimney collapse and damage historically has been one of the most common forms of damage in earthquakes across the country, yet remains one of the most commonly ignored items during earthquake-preparedness efforts. Even low level ground shaking can cause catastrophic damage and/or chimney failure. One could go as far as to liken a chimney to a canary in a coal mine.
CHIMNEY SAFETY SHOULD BE A HIGH PRIORITY FOR HOMEOWNERS
Many chimneys are built of unreinforced brick or stone. During an earthquake, these can fail and collapse or break and fall on the roof. In the 1994 Northridge, CA earthquake, approximately 60,000 masonry chimneys were destroyed or damaged beyond repair. Most chimneys tend to break at the roofline and fall away from the home. However, some chimneys can fall into the home, causing serious injury and/or death to anyone inside at the time of collapse. Make sure to tell your friends and family members to avoid being anywhere near chimneys and fireplaces during earthquakes. It is also best to avoid locating patios, play areas, or parking spaces near a questionable chimney.
HOW TO IDENTIFY A DAMAGED CHIMNEY
Homeowners who are comfortable enough doing minor DIY projects around the house can do a few things to check on the status of their home’s chimney. Checking the mortar between the bricks or stones with a screwdriver is a solid first step; if it crumbles when you pick at it, the chimney may be a hazard. Inspecting the attic and floor spaces for metal ties that should be holding the chimney to the house is a good second step; the absence of said ties should be an immediate red flag to homeowners. Determining whether a chimney is susceptible to earthquake damage is not always easy. When in doubt, contact a licensed professional.
DON’T BE AFRAID TO TAKE ACTION TO PROTECT YOUR FAMILY
If it is determined that your chimney is damaged, don’t be afraid to have it professionally torn down and reconstructed. It is far better to play it safe and spend a little additional to err on the side of caution than to take your chances and have something happen to one of your loved ones. There are several precautions you can take to reduce the risk of damage from falling chimneys should you opt to not have a complete rebuild completed:
• Add plywood at the roof or above the ceiling joists to prevent brick or stone from falling into the house. This can be completed by layering plywood above the ceiling in the attic or nailing plywood under the shingles when reroofing.
• Replace the upper portion of the chimney with metal flues.
• Have a licensed professional and/or engineer strengthen and reinforce the existing chimney.
When opting to go the route of rebuilding or reinforcing your chimney, always remember to first consult the local building and codes officials to obtain necessary permits (most professionals will handle this for you).
According to FEMA, 45 states and territories in the U.S. are at moderate to very high risk for earthquakes. Shaking ground accounts for 99% of earthquake-related damage to residences. The extent of damages caused by an earthquake is typically more substantial if a home hasn’t been prepared for an earthquake before it happens. Homeowners can take appropriate measures to ensure the soundness of their chimney by having it inspected annually by one the CSIA-certified chimney professionals at Northeastern Masonry & Chimney. We look forward to serving you and your family for years to come!