Chimney repair in Circle Pines & Lexington, MN

What seventy winters does to mortar

Mortar is supposed to wear out before the brick does. After this many freeze and thaw cycles, the joints above the roof are often soft enough to dig out with a key. Once they're open, the chimney soaks up water, the water freezes inside the brick, and the faces come off. Then you're not repointing anymore, you're rebuilding, and it's a much bigger job. The gap between those two is usually two or three winters.

The original crowns

A lot of chimneys from that era were finished with a thin coat of mortar smeared over the top instead of a real poured crown. No overhang, no drip edge. They crack early and send every rain straight down into the chimney. Replacing that with a poured crown that hangs past the brick is the one fix that saves the brick on one of these houses.

What's inside a chimney this old

The flue is the passage the smoke goes up, and in most chimneys from the 1950s on it's lined with square clay tiles stacked on top of each other. After seventy years, some of those tiles crack, and the mortar between them washes out. Heat and creosote then get into the brick around the flue, which is the part of the chimney you can't see from anywhere. That's why the camera goes all the way down on every inspection we do on these houses.

Circle Pines: the 1950s houses and the 1980s ones

Circle Pines built 28% of its houses in the 1950s and another 27% in the 1980s. The 50s houses are the ones with original brick chimneys and thin mortar caps on top. The 80s houses are thirty-some years in, which is when the first crack in the crown and the first open joints above the roof show up. 70% of Circle Pines homes are single-family houses, and 87% are lived in by their owners, so most chimneys here belong to the person reading this.

Lexington: small town, a lot of shared roofs

Lexington has about 1,249 homes, and fewer than half of them, 46%, are single-family detached. If you're in a townhouse, a duplex or a small building, the chimney may serve more than one unit, and a repair on it is a conversation with your neighbors or your association too. We photograph the whole chimney and put it in writing, so everybody who shares it sees the same thing.

The weather these chimneys sit in

The nearest NOAA station with a solid record is at Vadnais Lake, about seven miles south of both towns. Over the seven complete winters it recorded since 2015, it averaged 74 days a winter that went above freezing in the day and below it at night, and about 18 nights at zero or colder. It runs a little warmer than the stations farther north, but 74 freeze-thaw days is still 74 times a winter that water in an open joint freezes and pushes.

Why that's hard on seventy-year-old mortar

The first freeze at that station came around October 27 and the last around April 22 in a typical year. Six months of freezing and thawing on a mortar joint that's already soft is how a chimney goes from needing a repoint to needing the top rebuilt. The mortar gives out first because it's supposed to. Once it does, the brick is next.

Chimney inspection in Circle Pines and Lexington

On the 1950s brick chimneys we look hardest at the top: whether there's a real crown or just a mortar wash, how deep the joints have worn above the roofline, whether the flashing is metal or a tar patch, and the clay flue tiles with a camera. On the 80s houses we check the same things and the liner in the fireplace. Every flue in the chimney gets looked at, including an old furnace or water heater flue, and you get the pictures by email.

What our inspections turn up

The crown showed up in 225 of the 418 repair scopes we've written, more than anything else. Tuckpointing came up in 89. On brick chimneys specifically, 76 of 234 scopes included open joints that needed repointing. We've done 773 inspections since 2022, and these are the company-wide numbers, not a count from these two towns. On chimneys as old as these, the crown and the joints are where we'd look first.

Chimney sweep in Circle Pines and Lexington

A lot of fireplaces in these houses get lit a few times a year, and some haven't been lit in a long time. Either way, the sweep comes with the inspection. We look at every flue, and if there's more than an eighth of an inch of buildup, it gets swept that same visit. If a fireplace hasn't been used in years, the inspection matters more than the sweep: birds, a broken flue tile or a crumbling crown won't show from the living room.