Commonly Asked Questions About Chimneys:
There are many reasons why your house may smell smokey: One of the main reasons is the location of your chimney. If your chimney is located outside of the building (i.e. on an outside wall of the house), this may be the reason. Let me explain. A house typically has all windows and doors closed. This leads to two different pressure zones. The upper part of the house will be filled with warm air (+ air) which will be pulling upward, and the lower part of the house will be filled with cold air (- air) which will be pulling downward.
See Figure 1
If you have a fireplace located on the second floor, chances are it will draw efficiently. That part of the house is filled with warm, upward-pulling air. If you have a fireplace located in the basement, chances are it will not work because you are dealing with cold, downward pulling air (first-floor fireplaces can go either way). If you smell smoke during the fire, after the fire, or when the air conditioner is on, there is a good chance your house is losing positive air (like letting air out of a balloon). The house has to make up for this loss of air through whatever opening it can find. In this case, the opening is your fireplace. Example: If you leave a second-floor window open, the house will act better as a chimney than the chimney will (See Figure 2).
The exact opposite is true also. If you leave only a basement window open, the house will have more positive pressure in it (See Figure 3).
Many things in your house can affect this pressure. Any breach in the ceiling level can be a problem. An attic hatch, recessed can lights, bathroom exhaust fans without baffle, unsealed windows, and air conditioning ducts coming out of the ceiling are typical causes of the smelly problem. In the basement, the same problem can occur. Look around the 4” sewer stack as it is going through the first floor and make sure it is sealed properly. Look around the masonry chimney and any other thing that may be penetrating the first floor that goes up to the attic. If any of these items has a clear shot to the attic, the basement will be continuously losing air and can give you this smelly problem.
“How can I tell if any of these things are happening in my house?”
Generally, there is one main thing to look for: cobwebs. Cobwebs are not caused by spiders. They are caused by the continual flow of warm-to-cold air or cold-to-warm air. So, if you see cobwebs around your attic hatch, there is a strong possibility that you are losing heat out of your house continually and your house is acting as a chimney. The smell of smoke coming down the chimney is a result of your house losing too much air from the unsealed attic hatch. That air has to be replenished because your house is not going to implode, and so it is going to reenter the house in whichever way it can. Since there are no windows open, it is going to come right down the chimney and give you the smell. No one knows your house better than you. Look to find what ways air can be leaving your house. It is generally a simple and inexpensive problem to fix. Test: A good test you can perform yourself involves a cigarette and a strong flashlight. Make sure your house is closed tight for at least a few hours before you do this test. Light the cigarette and go around the house testing those areas I described above and any others you can think of that apply to your home. Let the smoke linger around those areas and hold the flashlight in a manner in which you can easily determine if smoke is leaving your building. If you do not want to perform this test on your own, we would be happy to come out and give you a consultation.
Chimney Drafting Problems Solved
Smoke Stacks, Inc. can solve your chimney drafting problems, whether it be from pressure issues to bad chimney liners (Flue Tiles) or chimney sizing issues.
The most important thing you should know: Water ruins masonry. Therefore, it is to your chimney’s advantage to avoid as much moisture as possible. Exterior moisture such as rain and snow can be limited with proper construction. Interior moisture in the chimney cannot be limited. Furnaces generally produce one gallon’s worth of water every hour they run. Additionally, hot water heaters generally produce a half gallon’s worth of water every hour they run. The interior lining of your chimney is being ruined by this constant flow of moisture. As time passes, the interior liner of your chimney is becoming less able to confine the products of combustion. Failure is often the end result.
No matter what anyone tells you, there is one thing you should know: Water ruins masonry. To avoid the problems associated with external water penetration of the chimney, the uppermost part of the chimney should overhang the chimney on all sides and be waterproof. Unfortunately, most chimneys built today, do not overhang the chimney on all sides and are not waterproof. This generally causes failure of brick and mortar on the chimney, and can also lead to water staining in the living quarters.
You could certainly coat the top of your chimney with a waterproof coating. Unfortunately, the coating will not be able to give your chimney a proper overhang on all sides. You could compare this to building a house without having an “eve” or overhang on all sides; no quality builder would recommend this. The rain and snow coming into direct contact with the sides of the building, whether made of brick, stone, or wood siding would make maintenance on those surfaces an annual event.
Between the flue or liner and the masonry, brick or stone around your chimney, there is an air space of one inch which allows for the liner to expand and contract. Once a liner fails, the wet and moist gases penetrate into this one-inch air space and come into direct contact with the exterior masonry. Therefore, repairing only the masonry will not correct the condition of moisture penetration through deteriorated flue lining from below.
Absolutely. Your older-style masonry chimney was meant to vent a lot of heat. With the advent of newer, more efficient appliances, the small amount of heat being put up the chimney will almost all condense. If you don’t believe that, try this when the temperature is cold outside: Let everyone in your house take hot showers, wash the dogs, and do your laundry. Go outside and see if any ‘smoke’ is coming out of your chimney. There is a good chance there won’t be any. Do this same thing once you have installed the appropriate size liner. It will smoke shortly after you are on your first shower.
I almost always recommend a new liner. The only chance you will not need one is if you have an older natural venting appliance and the flue tiles are in good shape. The reason for this is that the older appliances send a good amount of heat up the chimney. The gases then have limited condensation time. All newer appliances are going to need a new liner. They are just too efficient.
If you have a wood-burning stove venting into a lined or unlined masonry chimney, you need a new U.L.-listed liner immediately. Wood-burning stoves experience chimney fires far too often, and the homeowner usually isn’t even aware of it. In this case, my father is my best example. He loved to burn wood and had two wood-burning stoves going continuously during winter. He had at least two chimney fires a year. In the attic, there was black soot oozing out of the chimney. He finally let me reline the chimney once he saw all of the ignited soot.
95% of water leaks are attributed to the flashing. If water passes through the flashing, it can run right down the chimney and onto your ceiling or fireplace facade. Furthermore, most of the flashing we find in the field is not done correctly. Let me explain. The flashing on your chimney needs to be able to move. The roof on your house is going to expand and contract as it heats up and cools down. The masonry chimney is not going to move. Therefore, you need to have a flashing that is going to be step flashed and then counter flashed.
