Old homes more than sixty years old were mainly masonry based, meaning they were made with bricks and mortar or concrete blocks. Metal built hearth systems were installed in homes built after 1950. Masonry based fireplaces on older homes commonly need to be repaired in order for them to be safe to use.
Many older chimneys were not lined, and because of this your fireplace is unsafe to use. Even if it has been used, there are problems with this chimney system that make it dangerous. fireplaces with no lining can:
- Have bad draft characteristics, meaning the smoke won’t flow up the chimney properly and can cause damage to your home or health.
- Can leak gases into your living space
- Condensation can adhere to the chimney with ruins wallpaper and causes masonry problems on the fireplace. Condensation can assist the formation of tar and creosote which is flammable and can catch fire to your home.
Other than dangers, if your old fireplace isn’t lined and you want to make changes to the structure, you must bring the chimney up to current building code standards and an unlined chimney will not pass. If you’re wanting to install a new furnace, boiler, or wood stove, you’ll have to line the chimney first.
Also, insurance companies in Toronto may deny your claim if you make changes without improving the fireplace.
Old brick and mortar fireplaces also experience problems with the masonry age. Older bricks are often actually better than newer bricks, however if proper mortar techniques were not used and the brick surfaces were not maintained with a good seal against the weather, the brick begins old and porous and will easily begin decay. At that point, the brick needs to be replaced.
Wind, sun, rain, all work to wear down your chimney materials and over time it just becomes necessary to repair your chimney. If the bricks hold water because they’re in a moist and shaded area, they degrade faster. That’s why proper sealing against moisture is important in masonry.
Shifting ground can be an issue with your fireplace no matter its age. The ground is always moving slightly, however there are times when the foundation shifts with the ground structure and the masonry on your chimney or home could crack. Rainwater gathering around the foundation can cause soil erosion underneath it, which causes an unstable surface for your foundation and home to sit on. Tree roots can also cause foundation problems.
The crown on a fireplace may be missing or damaged. The crown is the cement top part that covers the chimney and protects it from the weather. Crowns aren’t as thick as a brick structure and can easily crack. If it is bad enough and repairs for the crack aren’t feasible, it will need to be removed and re-laid.
Debris can get inside the chimney from trees or rodents like squirrels nesting. This can cause erosion in the space. Installing a chimney chase cover prevents further problems and protects the fireplace from harsh weather conditions that can blow tree branches and other debris around.