Chimney and fireplace service in Minneapolis and its first-ring neighbors

The Census Bureau's 2024 American Community Survey puts 42.8 percent of Minneapolis housing units in buildings from 1939 or earlier, against 11.7 percent across the country, and the city's median home dates to 1951. Another 8.1 percent of units sit in two-unit buildings, roughly four times the Minnesota share. That adds up to a city full of brick stacks that have stood through eighty to a hundred-plus winters, many of them serving two households.

Just past the city line the age profile shifts by a generation. Nearly half of Richfield's homes, 47.8 percent, were built between 1940 and 1959, and Columbia Heights has a third of its housing from the same two decades. Those postwar houses usually have a modest brick chimney with a fireplace flue beside a smaller flue for the furnace and water heater. Gas heats about 70 percent of Minneapolis homes and more than 73 percent in both suburbs, while wood is the main heat in fewer than two homes in a thousand, so the flue that matters most is usually the one in the basement.

Gas appliances in an old brick flue

Minnesota's fuel gas code, Minn. R. 1346.5501, says an approved metal liner shall be installed in a masonry chimney that vents gas appliances. Furnace exhaust carries a lot of water vapor, and in a clay tile or bare brick flue that vapor condenses, soaks the mortar and freezes. The signs show up as white staining on the stack, crumbling joints near the top and tile shards in the cleanout.

The same code section forbids connecting any appliance to a flue that already serves a fireplace. In a duplex where the upstairs and downstairs furnaces, two water heaters and a fireplace all share one stack, we trace every connector to its flue at the free inspection and write down what each flue serves before we price anything.

• Aluminum liner for gas appliances only: $625 – $2,250
• Stainless steel liner, installed: $900 – $3,800
• Tuckpointing the stack once the flue is sorted out: $500 – $2,500

Historic districts and city permits

Minneapolis lists most heating and gas piping work as needing a mechanical permit, and no chimney or fireplace item appears on the city's list of exempt work. Homes inside a designated historic district also go through review by city preservation staff, which the city says can take several weeks. We check what the city requires for your address before we quote, and for historic properties we help you prepare photos and a written scope for the application.

What a Minneapolis winter does to masonry

NOAA's 1991–2020 normals for MSP airport show about 147 nights a year at or below freezing, about 22 nights at or below zero and about 51 inches of snow. Our own arithmetic on those normals gives about 75 days a year that freeze overnight and thaw by afternoon. Each of those cycles drives water a little deeper into a cracked crown or an open joint.

Big storms add to the load. The DNR State Climatology Office records 28.4 inches at MSP in the 1991 Halloween Blizzard, still the single-storm record, and a low of minus 28 degrees on January 30, 2019. Snow banked against a chimney melts against warm brick for weeks, which is why we look closely at the flashing and the uphill side of the stack.