Do you live in a beautiful, historic old home? You probably love the unique charm that your home has to offer, and the fact that your home doesn’t look just like everyone else’s. But if you have an older home with fireplace, there are certain problems you should be on the lookout for. Older chimneys (any before 1950, and definitely any that are from the 19th century) were constructed with fewer regulations and requirements than the chimneys of today. Many of these regulations are in place for the safety of you and your house, so before you use that old fireplace again, get a professional to check out the chimney!
Chimneys built before the 1950s were either masonry or block chimneys. Amazingly, bricks that were made in the 16th and 17th centuries are actually much more durable than bricks produced today, but the mortar is what can wear out. The mortar is what hold the bricks in place, so if it is damaged or eroded, the entire chimney can begin to lean and even collapse. But there is no need to have your chimney meet such an unfortunate end—with tuckpointing you can restore the lost mortar and integrity of your chimney. With tuckpointing, the old mortar is removed and new mortar is inserted between the bricks. Not only does tuckpointing make your chimney look great, it restores the structural stability of your chimney and gives it many more useful years. Block chimneys present their own set of problems, and while they do work, they are not as desirable as brick chimneys. Most block chimneys are meant to be covered with bricks, and without them are more prone to leaking, cracking, or leaning. Block chimneys built right against the side of a wood frame house are usually illegal and can pose a fire hazard. While you could attempt to cover the blocks with bricks, there is usually not enough room to do so safely, and the chimney should be rebuilt properly.
Chimneys in older homes can be unlined, and this is a surprisingly big deal. As a general rule, an unlined chimney should not be used. Chimney linings help prevent noxious gases from leaking back into your living space, threatening your health and safety. Chimneys that are unlined can also build up dangerous levels
of creosote and tar that can pose a fire risk as they cling to the bricks. In many areas an unlined chimney will have to come up to code (be lined) if you are making changes to your home, and especially the area around the chimney. Another problem with unlined chimneys is the amount of condensation that can be produced. Especially true with gas fireplaces, condensation can build up and adhere to the masonry. This can lead to damage of your chimney during freeze and thaw cycles, and can even ruin your wallpaper or drywall in your home. Chimneys that are unlined can have diminished performance due to poor drafting, and may be the reason your home never seems to warm up. A final reason to make sure your older chimney is unlined is that your insurance may not cover you if your chimney is not updated! For your health, safety, and keeping your home in good condition—line your chimney!
What in the world is pyrolysis and why do you need to worry about it with older fireplaces? Pyrolysis is a chemical reaction that causes organic materials (usually wood in the case of a home) to decompose when they are exposed to heat over a long period of time. Because in older homes there was not a standard for keeping chimneys and fireplaces at a distance from combustible materials, many older chimneys could be resting on wood parts of the house. The other problem with pyrolysis is that it can take many years to occur, so a chimney that has seemed “safe” for a hundred years can suddenly become a huge safety hazard. It is common in older homes to see wood 2x4s right against the bricks of the chimney, and this is putting your home and safety at risk. If you have an older home you should have your chimney inspected to be sure that you are not at risk for pyrolysis.
Something that is often missing on older chimneys is a chimney crown. This is the cement part on top that keep rain from getting into your chimney. The crown takes the brunt of the sun, wind, rain, and snow and protects the chimney. Even if your older chimney does have a crown, it is very likely cracked if it hasn’t been attended to in awhile, and should be replaced. Another option for the top of your chimney is a cap, which is usually made of metal and can provide protection not just from the elements, but can keep sparks from coming out of your chimney and causing any external damage.
Bricks are great at soaking in water, which can be okay if your bricks are south-facing and can dry off in the sun. But when your chimney bricks are shaded and are constantly exposed to water, they can freeze in the winter and cause damage. You may need to waterproof your masonry if it is not able to fully dry out after a rain or snow storm. If you do decide to waterproof, you want something that still allows the pores of the bricks to stay open and breathe.
If you have an old chimney, you should have it inspected to make sure there aren’t any of these common problems present. If you are needing chimney repair in Frederick, call Chimney Care Plus to ensure that your chimney is safe and operating well.