Any number of conditions can contribute to smoking problems in a wood-burning fireplace. In some cases, some relatively simple measures may improve conditions. In others, further evaluation and extensive repairs may be necessary.
The first step in most cases is to arrange for an inspection or cleaning of the chimney flue. A certified chimney sweep is usually the appropriate professional to contact for chimney cleaning or investigation of fireplace or chimney problems. Many sweeps now have equipment to take a video of the chimney flue so that you can see exactly what problems may lie within, as well as to confirm it was cleaned properly.
Here are some possible practical solutions to aggravating smoke problems:
Raise the hearth. A fireplace opening that is too large compared to the opening of the chimney flue can lead to poor drafting (the movement of the gases that result from the burning wood up the chimney). By building up the base of the fireplace, the opening will be decreased. To experiment with this approach, a sheet metal hearth can be supported on bricks placed on the existing hearth. If this change improves the draft, the hearth can be raised using firebrick masonry. The hearth extension can also be built up to the same level.
Add a canopy hood. An experimental model of a canopy hood can be made of sheet metal and temporarily attached over the top of the fireplace opening. Try various designs and sizes. If the hood works well, a permanent metal hood can be installed.
Extend the chimney. The higher the chimney, the better the draft. A good draft is usually provided by a chimney which is 20 feet or more higher than the hearth. If the existing chimney is short a good draft may just not be able to develop. One or more metal chimney sections can be temporarily installed on top of an existing chimney to test whether the draft is improved before a more permanent (and expensive) fix is tried.
Move the chimney. If your chimney has been built in the wrong place – it might be too far over or too far back – you may need to change its position. To do this, you’ll need a professional roofer, such as Stourbridge Roofing Pro’s, to alter your roof for you. The chimney will need to be taken down, the roof will need sealing up, and a new hole will need to be made for the chimney’s new position. This should fix any draft issues you have and also give you the chance to redesign your chimney entirely.
Trim surrounding trees. Wavering smoke patterns above the chimney may indicate that tall trees are causing a downdraft (air forced down the chimney by the wind). The surrounding trees should be trimmed and/or the chimney flue height extended to prevent this condition.
Add a chimney cap or flueguard. If a downdraft appears to affect the exhaust gases, adding a chimney cap or flueguard of metal or stone may help deflect the air before it entering the chimney.
These suggestions for correcting smoking fireplace conditions may be only the first step in some situations. If there are major fireplace deficiencies or the chimney is deteriorated, more drastic measures will be needed. The only practical options in severe cases may be to rebuild the fireplace and/or chimney. A less expensive option would be to retrofit a masonry fireplace or chimney with a gas-fired fireplace coupled with a new metal flue inside the defective chimney – or to use an electric fireplace and seal off the old chimney. Simply maintaining a small fire may help as well.
More home safety and maintenance information is available online at www.housemaster.com.