Chimney Rebuilds: pride in craft - the MC Special

When deterioration of the chimney is such that brick replacement and tuckpointing are not sufficient to repair it, a rebuild is in order. During a rebuild (or partial rebuild), the deteriorated brick courses (rows) are removed to the point where the chimney structure is solid and intact, and the chimney is then rebuilt with new bricks and fresh mortar, topping it off with a newly constructed crown. 

Our MC Special is a roofline tear-down and rebuild finished with a beautiful stylized-form crown, including a built-in overhang and drip edge, available in Top Rib or Victorian style.

​Masterfully built for optimal performance, aesthetics, and longevity. 

Tear-down & rebuild: step by step

Since deterioration usually starts from the top down, as water seeps through cracks in the crown and the damage works its way downward, the tear-down begins with removal of the crown, followed by each subsequent course (or row) of bricks until solid structure is reached, usually at the roofline. The chimney is then rebuilt back to its original height and style using matching brick. The process usually involves a 3-person team and takes 2 days to complete.

Severe disrepair

In this example, tiny cracks in the chimney crown begin the slow process of deterioration from water intrusion. As the water infiltrates the porous masonry, it expands and contracts with the freeze-thaw cycle, leading to larger cracks, spalling brick, and damage to the interior chimney. The only remedy to this level of disrepair is a rebuild, which is what our project manager recommended in this case.

Tearing down

After removal of the chimney crown, a hammer drill is used to break down the mortar and loosen the bricks, course by course. Extra care is taken when working in close proximity to the flue tiles. Removal proceeds to the point where the structure is stable and undamaged at the roofline. Bricks and other debris are removed and properly disposed of. 

Resetting flue tiles

Once the surrounding chimney chase is removed, misaligned flue tiles can be seen, as well as gaps in the mortar. Any space between flue tiles allows the escape of toxic gases and smoke from the flue through these openings, creating a potentially dangerous situation. Additionally, gaps in the flue will prevent the proper draw of smoke up the flue, which could result in backdrafting into the living space.

Parging the flue

Before the rebuild can begin the misaligned flue tiles are removed. High-heat refractory mortar is applied to the inside of each tile and smoothed with parging tools. Mortar is then applied generously to the top and bottom of each tile, and they are placed squarely one on top of the other. A trowel is used to apply additional mortar around any gaps to ensure they are thoroughly closed. This process leaves the flue properly sealed and functioning optimally. 

Rebuilding courses

With the flue tiles properly positioned, the chimney is methodically rebuilt, row by row, using brick closely matched to the original. Beginning at the roofline, the mason lays mortar around the row, setting each brick in place and then ensuring it is level from side to side and front to back. The process is repeated until the row count is equivalent to what it was before, leaving the flue tiles exposed a minimum of 4 inches above the crown. 

Constructing the crown

Our MC Special utilizes a custom mold with a built-in drip edge. The mold is securely ratchet-strapped to the newly built chimney. A durable crack-resistant concrete mix is poured into the mold and reinforced with rebar and wire mesh. Expansion joints are installed around the flue tiles to accommodate expansion and contraction. Finishing tools are used to give it a slight pitch to facilitate water runoff. The crown is then wrapped with an insulated concrete curing blanket that keeps moisture out and heat in, aiding the curing process. 

The masterpiece

After 2 days, the crown has sufficiently cured. The original chimney caps, if they are in good condition, are reinstalled, and if not, they are replaced with new ones. (Every flue needs a cap to prevent water and animal entry!) The entire structure is protected with a breathable water repellent.

​The newly built chimney is an eye-catching addition to the outside of the home. And on the inside, it's fully restored to safe and optimal functioning.

Free estimate + consult

Chimney repair can be a major expense, and the quality of workmanship has a direct impact on your home's safety and value. We know you want to get it right. Our estimate + consult is designed to give you the tools you need to make an informed decision about your chimney repair project. 

Request an Estimate

Reach out

info@mnchimney.com
612-806-6970
M-F, 8 a.m. - 5 p.m.

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