Chimney Repair & Masonry in DeKalb, IL

Chimney repair covers the masonry and weatherproofing that keep your chimney standing and dry: repointing crumbling mortar, rebuilding spalling brick, sealing or replacing the crown, and fixing the flashing where the chimney meets the roof. Illinois freeze-thaw winters are hard on brick, and small cracks turn into big leaks fast. Imperial has repaired DeKalb-area chimneys since 1987 — we find the source of the problem and fix it, not just patch the symptom.

Signs your chimney needs repair

White staining (efflorescence) on the brick, crumbling mortar joints, rust on the damper or firebox, a cracked crown, or water stains on the ceiling near the chimney all point to water getting in. Caught early, these are straightforward fixes. Left alone, they lead to a leaning stack or a full rebuild.

Tuckpointing and brick repair

Tuckpointing grinds out failed mortar joints and repacks them with fresh, color-matched mortar — restoring both the look and the structural bond of the chimney. Where individual bricks have spalled or cracked from freeze-thaw, we replace them so the stack sheds water again.

Crown and flashing repair

The crown is the concrete slab on top of the chimney; when it cracks, water pours straight into the masonry. We seal or rebuild it. At the roofline, we repair or replace the flashing and seal it properly — the most common source of a chimney leak.

Waterproofing and leaks

Once the masonry is sound, a vapor-permeable sealant lets the brick breathe while blocking rain — stopping the freeze-thaw cycle that caused the damage. If your chimney is already leaking, we trace it to the crown, flashing or brick and fix the actual source.

Tuckpointing, repointing and rebuilding — the difference

These terms get used loosely, so here is how we mean them. Repointing removes deteriorated mortar from the joints and repacks them with fresh mortar — the core repair for a chimney with washed-out or crumbling joints. Tuckpointing is a related finishing technique that also refines the look of the joint. A rebuild is reserved for masonry too far gone to repoint — where brick has spalled badly or the stack has begun to lean — and involves taking the chimney down to a sound course and rebuilding above it. We recommend the least-invasive option that will actually last, not the biggest ticket.

Matching old brick and mortar the right way

On an older chimney, using the wrong mortar is a common and costly mistake. Hard, modern high-portland mortar on soft antique brick is stronger than the brick itself, so as the wall moves and weathers the brick spalls instead of the sacrificial joint. The correct approach matches the new mortar’s strength and composition to the original — often a softer, lime-rich mix on historic masonry — and color-matches it so the repair blends rather than standing out. We also source replacement brick to match. Done right, a repair reads as part of the original chimney, not a patch.

When a repair becomes a rebuild

Homeowners often ask where the line is. As long as the brick is largely sound and the damage is confined to the mortar joints, the crown or the flashing, we are in repair territory — repointing, sealing, waterproofing. Once the brick itself is spalling widely, the stack is out of plumb, or water has compromised the structure, patching only buys a little time. A camera and a close look tell us which situation you are in, and we give you the honest answer, because rebuilding a chimney that only needed repointing is as wrong as repointing one that needs a rebuild.

Serving DeKalb County and the surrounding towns

We bring this service across DeKalb and 20-plus nearby towns, from Sycamore and Cortland to Sandwich, Genoa and Rochelle — see the full service area. Related work: Caps & Crowns Chimney Relining Chimney Inspection.

Why an open masonry fireplace never seems to warm up

A traditional open fireplace is a poor heater by design: most of the heat goes up the flue, and a plain box-shaped firebox makes it worse. Square side walls and a vertical back wall soak heat into the brick instead of reflecting it into the room, and a wide, unshaped throat lets the fire pull far more room air than it needs — air you already paid to heat. On a cold DeKalb night that fireplace can move more warm air out of the house than it puts back in.

The shape of the firebox is what we can change. A firebox rebuilt with angled sides and a fireback that slopes forward above the grate throws radiant heat outward, the way a properly proportioned Rumford firebox does. Parging a rough, stepped smoke chamber into a smooth funnel lets smoke leave with less turbulence, and narrowing an oversized throat cuts the volume of room air the fire draws. These are masonry jobs done from inside the firebox with firebrick and refractory mortar, and we pair them with a Level 2 inspection so we have seen the throat and smoke chamber before quoting.

If the goal is real heat rather than ambience, the honest answer is sometimes an insert: a sealed wood or gas unit with its own liner turns an open hearth running near 10 percent efficiency into a heater running above 70. We will tell you which route fits your chimney.