How often should a chimney be swept in Illinois?

The short answer is once a year. The EPA's Burn Wise program and NFPA 211 both put an annual inspection on the calendar for any chimney that vents a fireplace, wood stove or gas appliance, whether or not you burned much last winter.

An inspection is only as good as what the technician can see. Soot and creosote coat the flue walls and hide cracked tiles, gaps in the mortar joints and damage from past chimney fires. If the chimney is dirty, we clean it first so the inspection can actually find those problems. That is why cleaning and inspection go together.

Creosote is the obvious reason, but it is rarely the one that costs people money. In our part of Illinois the freeze-thaw cycle does more damage than smoke does. Water gets into a crown crack or an unlined joint in November, freezes in January, and opens the crack a little wider every night. By spring a hairline is a gap. A yearly look catches that while it is still a tube of sealant instead of a rebuild.

A household burning several cords a season, or burning unseasoned wood, may need a mid-season sweep as well. The rule of thumb sweeps use is one-eighth of an inch of creosote — at that point it comes out, regardless of the date.

Chimneys and fireplaces are covered by Chapter 10 of the International Residential Code (IRC), "Chimneys and Fireplaces." Most village building and zoning departments around here enforce it. Those codes exist for safety — to keep fire, heat and carbon monoxide inside the chimney and out of your home — so every repair we make is done to meet them.

August through October. Once the first cold snap arrives everyone calls at once, and any repair we find needs dry weather and mortar cure time. Booking early means the fireplace is ready the first night you want it.