Q. How often should I have my chimney cleaned?
This a tougher question than it sounds. The quick simple answer is: The National Fire Protection Association standard 211 says, "Chimneys, fireplaces, and vents shall be inspected at least once a year for soundness, freedom from deposits, and correct clearances. Cleaning, maintenance, and repairs shall be done if necessary." This is the national safety standard and is the correct way to approach the problem. It takes into account the fact that even if you don't use your chimney much, animals may build nests in the flue or there may be other types of deterioration that could make the chimney unsafe to use.
The Chimney Safety Institute of America recommends that open masonry fireplaces should be cleaned at 1/4" of sooty buildup, and sooner if there is any glaze present in the system. Factory-built fireplaces should be cleaned when any appreciable buildup occurs. This is considered to be enough fuel buildup to cause a chimney fire capable of damaging the chimney or spreading to the home.
Q. My fireplace smokes. What can I do?
There are a multitude of reasons for smokey fireplaces. We have included an entire section on smoking fireplaces in the fireplace area and we suggest you go there for a better discussion of this problem.
Q. My fireplace stinks, especially in the summer. What can I do?
The smell is due to creosote deposits in the chimney, a natural byproduct of wood burning. The odor is usually worse in the summer when the humidity is high and the air conditioner is turned on. A good cleaning will help but usually won't solve the problem completely. There are commercial chimney deodorants that work pretty well, and many people have good results with baking soda or even kitty litter set in the fireplace. The real problem is the air being drawn down the chimney, a symptom of overall pressure problems in the house. Some make-up air should be introduced somewhere else in the house. A tight sealing, top mounted damper will also reduce this air flow coming down the chimney.
Q. When I build a fire in my upstairs fireplace, I get smoke from the basement fireplace.
This has become quite a common problem in modern air tight houses where weather proofing has sealed up the usual air infiltration routes. The fireplace in use exhausts household air until a negative pressure situation exists. If the house is fairly tight, the simplest route for makeup air to enter the structure is often the unused fireplace chimney. As air is drawn down this unused flue, it picks up smoke that is exiting nearby from the fireplace in use and delivers the smoke to the living area. The best solution is to provide makeup air to the house so the negative pressure problem no longer exists, thus eliminating not only the smoke problem, but also the potential for carbon monoxide to be drawn back down the furnace chimney. A secondary solution is to install a top mount damper on the fireplace that is used the least.
Q. I heat with gas. Should this chimney be checked too?
Without a doubt! Although gas is generally a clean burning fuel, the chimney can become non-functional from bird nests or other debris blocking the flue. Modern furnaces can also cause many problems with the average flues intended to vent the older generation of furnaces. We suggest you check the areas on gas and carbon monoxide for more information.
. Questions of a Do It Yourself nature should be submitted to our "
1) On the chimney cleaning topic.. I know CSIA says 1/4 inch is OK but 1/4 inch of buildup is a bit too much before a cleaning should be done. If the deposits feel sticky or look shiny it is best to have it done right away.
2) On fireplace stink...A chimney top damper will seal in the odors, so that advice is misguided. It is best to seal the chimney off low and tight with a chimney balloon. This will seal the fireplace chimney off from the rest of home. If you have any left over aroma you can use a salad bowl of vinegar set in the hearth for a few days.
3) On smoke that gets sucked into the other chimney...A chimney top damper will work if you are having smoke crossover. But, who wants to spend $500-$750 to have a chimney top damper installed on a fireplace you hardly use? A less expensive option is to either put a chimney balloon in just above the hearth in the downstairs chimney, or if you NEVER use that fireplace you can put a simple cap on the top of it.