Chimney repair and masonry work in Bourbonnais and the surrounding towns

By Jacob Dove, founder of Friendship Chimney Sweep · 29 years in the trade

Water is the enemy of a masonry chimney

Almost every chimney repair we do in Kankakee County traces back to water. Rain and snowmelt soak into brick and mortar. Then a January night drops to five below, the water freezes, expands, and pops the face off the brick or opens the joint. The next thaw lets more water in. After a few winters the crown is cracked, the top courses are loose, and water is running down the inside of the chimney onto the damper and firebox. Our repairs are ordered to stop that cycle first, then restore what it damaged.

Tuckpointing and brick replacement

Tuckpointing means grinding out the failed mortar to a proper depth, usually about three-quarters of an inch, and packing in new mortar in lifts. Two things matter that many crews skip. First, the new mortar has to match the strength of the old brick; a hard modern mortar on soft 1920s Kankakee brick will crack the brick instead of the joint. We use a Type N or a softer lime-rich mix on older chimneys and Type S only where the brick can take it. Second, the joint profile should match the original so the repair does not show. Spalled bricks come out one at a time and are replaced with matching size and color from our reclaimed stock or a matched new brick.

Crown repair and rebuild

The crown is the concrete slab across the top of the chimney that sheds water away from the flue. A crown built the way we still see them, as a thin wash of mortar with no overhang, cracks within a few years. A crown with hairline cracks can be sealed with a flexible crown coat. A crown that is broken, sunken, or missing its drip edge gets rebuilt: formed, reinforced, poured with a proper overhang, and given an expansion gap around the flue tile so it does not crack again when the tile heats up.

Flashing and leaks

If water shows up on the ceiling next to the chimney, the flashing is the first suspect. We reset or replace step flashing and counterflashing, cut a new reglet into the mortar joint where the old one was caulked to the brick, and seal it properly. Where the chimney sits on the low side of a roof we recommend a cricket, a small peaked diverter that keeps snow and water from piling against the back of the chimney.

Firebox and smoke chamber

Firebrick and refractory mortar in the firebox take direct flame and eventually crack or fall out. We repoint firebox joints with refractory mortar rated for the heat, replace cracked firebrick, and parge rough corbeled smoke chambers smooth with a refractory parging mix so they draft better and hold less creosote. Prefab fireplaces get new refractory panels sized to the model.

Partial and full rebuilds

When the top of a chimney is leaning, the brick is spalled through, or the mortar is sand, tuckpointing will not hold. We take the chimney down to sound brick, usually somewhere below the roofline, and rebuild it with new brick, a proper crown and new flashing. It is a larger job and we say so plainly when it is the right call rather than selling you three rounds of patching.

Why an open masonry fireplace never warms the room

A traditional open masonry fireplace is a beautiful thing and a poor heater. Most of the heat a fire produces goes straight up the flue, and the fire pulls room air with it: a typical open fireplace moves several hundred cubic feet of already-heated air out of the house every minute while it burns. The room directly in front of the hearth feels warm because of radiant heat from the flames and the firebrick. The rest of the house gets colder, because the air that replaces what went up the chimney comes in through every gap around windows and doors. On a Bourbonnais winter night that trade is a net loss.

The design itself is the limit, not the condition of the brick. A shallow Rumford-style firebox with a steep back wall radiates more heat into the room than a deep box, and we can sometimes rebuild a firebox toward that shape during repair. A tight-fitting glass door set reduces the room air lost up the flue. For a fireplace that is expected to actually heat, the answer is an insert: a sealed steel firebox with its own liner that keeps the heat in the room instead of in the chimney. We will tell you honestly which of those three your fireplace is a candidate for.

Waterproofing

After any masonry repair we recommend a breathable siloxane water repellent on the exterior brick. It lets the chimney dry out from inside while shedding rain, and it is not a paint or a film that traps moisture. One coat, applied to a dry chimney, protects the repair for years.

How a repair job goes

1. Inspection with photos so we and you know exactly what is failing and why.
2. A written scope with options, from the essential repair to the complete fix, priced separately.
3. Scheduling around the weather. Mortar and crown work need temperatures above 40°F for a day or two, so late fall and early spring are busy.
4. The work, with the site cleaned every day and photos of each stage.
5. A final walk-through and, when it makes sense, a water repellent.

Repairs are quoted after inspection because no two chimneys fail the same way. Starting points for the common jobs are on our pricing page.