So, you want to learn how to build fireplace chimney? Here's a little info to get you started...

Since ancient times, people have gathered around the fire, for a cozy, relaxing feeling. However, fire cannot be that appealing, if it fills up the room with smoke and creosote. To avoid this, a proper chimney is a must and for that you must know how to build fireplace chimney. A chimney provides vent to all the by-products of combustion and hence makes the fire "smoke free" and enjoyable.

Major chimney related problems

Flow reversal or down drafting chimneys are a common problem, when just lighting the fire leaves the room filled with smoke. This happens when the cold air enters the room through the chimney or the air pressure within the house falls. Ensuring the upper draft of the chimney, before lighting the fire, can combat this. Cracking a window near the stove or fireplace, or stuffing non-combustible rock wool in the large gap between chimney and stove can also solve the problem. However, if there is wind related draft problem, then increasing the height of the chimney can be beneficial.

How to build fireplace chimney to combat draft related problems

You must know how to build fireplace chimney, which can combat draft related problems.

• Chimney heights: it is better to build a taller chimney, as it ensures more draft than a shorter one, other things remaining constant.
  
  
• Chimney diameter: chimney diameter has considerable effect on the draft of the chimney. A chimney should not have a diameter, which is too wide, in comparison to the diameter of the flue outlet of the stove.
  
  
• Chimney location: if possible, it is better to build a chimney having indoors location as it would stay warmer and hence draft better.
  
  
• Bends in the chimney: it is better to have as less bends in the chimney as possible, because each turn of the chimney lowers the draft. On an average, a 90° turn cuts off five feet from the effective height of the chimney.
  
  
• Shape of the chimney: a round chimney is better than a square or rectangular one. Insulation is preferable as it keeps the chimney warm.
  
  
• Tightness of home: a home should not be too tight so that it cannot have proper flow of air. Air is very much required to support combustion and for the proper draft.
  
  

Chimney and fireplace sizing

There are varied shapes and sizes of chimneys and fireplaces. However, for proper venting, their sizes should be somewhat proportionate. This can help to prevent the draft problems of the chimney.
To vent a freestanding stove, the chimney diameter should be same in size as the flue collar on the stove. Therefore, a six-inch stove should have a six-inch chimney to go with it.

The masonry fireplaces are built in various sizes, the popular sizes being; 32" to 36" Wide and 25" to 29" High. Here the ratio between the size of the chimney and the fireplace opening is 1 is to 10. That means the fireplace opening can be 10 times as large as the flue tile cross section.

Therefore, with all the knowledge gathered, you know how to build fireplace chimney and that to a perfect one. So now sit back and enjoy the smoke-free fire.