Ask the Architect

Fireplace frustrations

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Q. I read your column about fireplaces, and wonder why I can’t get a fire to burn properly in my chimney. All I get is smoke in the room. I’ve had the flue checked and know that the damper is working correctly, even if it is a little rusty. The worst part is that the house smells like smoke, even when we haven’t had a fire for months. Nobody can find anything wrong with it. What can I do?

A. Set up an electric fireplace in front of the real one, or play the yule log rerun on your TV. A client once complained of the same problem, and after much searching, I asked them to build a fire so I could observe their method. They started the fire too far forward, so the smoke climbed the walls and smoked out the room, setting off the smoke detector. Rule No. 1: Make sure the fire is directly under the flue opening and centered in the fireplace.

There are many reasons why a fireplace doesn’t function. Some are obvious; some aren’t. Here are some possible reasons why yours doesn’t work. 1) The chimney is too narrow compared with its height. 2) The opening is too wide and not high enough. 3) The opening is too high and not wide enough. 4) There’s no fresh-air intake near the fire to draw air upward. 5) The flue has cracks that haven’t been detected. 6) The chimney isn’t two feet taller than the closest part of the roof within a 10-foot area, so breezes aren’t carrying smoke away, but instead a vacuum builds and forces air down the chimney. Winds rolling over your chimney from the upside roof slope also blow smoke downward in your chimney.

7) The flue has an angle bend in it that’s too sharp. 8) The wood selected isn’t properly seasoned. 9) Your fire starter is too wet or too dense. 10) The chimney has an animal living in it and must be cleaned out and capped. 11) The chimney is wet on the inside, either from openings in the exterior surface or the mortared crown or because it has no cap. This isn’t a likely reason for the smoke problem, but there’s a remote possibility.

Since a fire needs fuel, oxygen and heat to burn, these reasons are basic to why you haven’t had success. The formula for a great fire is the right type of starter (an easy-burning tinder) at the bottom, air space between everything of one-half to three-quarters of an inch, and a dry, soft wood like pine above the tinder. Add oak or other hardwoods after the fire is going to create more brightness. Updraft is also essential. I’m certain that one of these reasons is causing your problem. Don’t use any treated or dressed lumber that can give off poisonous gases and creosote. Be safe and attentive. Good luck!

© 2018 Monte Leeper. Readers are encouraged to send questions to yourhousedr@aol.com, with “Herald question” in the subject line, or to Herald Homes, 2 Endo Blvd., Garden City, NY 11530, Attn: Monte Leeper, architect.