Smoky Fireplace and Draft Problems, Solved at the Cause

A fireplace works by draft: warm smoke rises and pulls fresh air in behind it. When that pull is weak, smoke spills out of the opening instead of going up. The reasons vary. The flue may be too small for the fireplace opening, the chimney too short for the roof around it, the damper partly closed or broken, or the house so tightly sealed that a bath fan or kitchen hood is pulling air down the chimney.

We test the draft, look at the damper and flue, and check what else in the house is moving air. Then we explain the cause and give you the price of the fix in writing. Often the answer is small: a damper that no longer opens fully, a nest half blocking the flue or a cap that is too restrictive. Sometimes it is the shape of the fireplace itself, and then the fix is a smoke guard across the top of the opening or, less often, a taller flue. We test before we suggest anything.

Signs you need this

• Smoke rolls out of the top of the fireplace opening
• The fire only behaves with a window cracked open
• A smoky or tarry smell comes back on rainy days
• Smoke appears when the kitchen hood or dryer is running
• The fireplace started smoking after a roof or window project

How we do it

1. Test the draftWe check the draft with the fireplace cold and warm, with fans on and off, to see what changes.
2. Check the hardwareWe look at the damper, the smoke chamber, the flue size and the chimney top for blockages or damage.
3. Explain the causeYou get the cause in plain words, with photos, and a written price for the fix.
4. Fix and retestAfter the fix we light a test fire or run a smoke test to show the fireplace drawing properly.

Why does my fireplace smell worse when it rains?

Creosote in the flue absorbs moisture, and damp creosote gives off a stronger smell. At the same time, when the fireplace is cold the air in the chimney can flow downward into the house, carrying that smell with it. In a region with as many damp days as ours, many owners notice the odor long before they notice any smoke.

A cleaning, a cap to keep rain out and a damper that seals tightly usually solve it. A top-sealing damper closes at the top of the flue and is priced at the inspection.

Can a chimney be too short?

Yes. A chimney that ends below a nearby roof ridge, a taller addition or even a big tree can be caught in swirling air that pushes smoke back down. Adding height is a real fix in some cases. One West Seattle Blog poster described a contractor extending a chimney 17 inches for better draft.

We only suggest an extension after testing, because a cap, a smoke guard or a damper fix is cheaper and often enough. Extending the flue is typically $600 to $1,500.

Is a smoky fireplace a legal problem as well as a nuisance?

It can be. Washington's rule WAC 173-433-110 limits smoke from any solid fuel device to an average of 20 percent opacity for six minutes in any hour, with an allowance for starting a new fire. A fireplace that smokes heavily through the chimney may exceed that, and during a burn ban any visible smoke is a problem.

The fixes that stop smoke from spilling into the room usually make the fire burn cleaner up top as well.