How to repair a brick chimney?
Brick fireplaces, whether wood or gas, are a cozy element that is the epitome of a home for many owners. However, a crack in the brick or masonry joint between the bricks is an early warning sign that the chimney is about to be destroyed. Patching cracks in a brick chimney can save you thousands of dollars for later repairs of the chimney and protect you and your family by reducing the chance of a chimney fire.
Small cracks in summer can turn into surprisingly large cracks next spring. Leaving these large cracks in the outer bricks will increase the penetration effect of rain, snow and ice. Then water begins to flow, sometimes between the outer bricks and the flushing, and sometimes even between the outer bricks and the chimney.
If left unchecked, these small events can accumulate and cause catastrophe on roofing systems and interior ceilings, insulation, wall studs, and even floors.
Requirements
- General rake
- Tuck pointing tool
- directed by
- Masonry fleas
- hammer
- Pointed trowel
- Wire brush
- Spatula
- Garden hose
- Cartridge gun
- Paint brush
- Safety goggles
- Safety harness (optional)
- material
- Hot mortar
- Latex gloves
- Grenade launcher
- Clean the rags
- Masonry sealing
Instructions
Not all repair projects require you to complete all of the following steps: Damage to a small chimney may require only superficial work. However, it is advisable to carefully inspect the chimney and do the necessary brick chimney repair.
- Redesignate the chimney brick mortar: The mortar holds the bricks together. The new mortar is smooth and durable, but seasonal elements shatter and crumble the mortar. Mortar is softer than brick, so mortar always deteriorates first. Repoint or tack point is the process of scraping fragile mortar and replacing it with new mortar.
- Caulking around the chimney and crown: The main way water can enter a house and cause damage is the connection between the chimney flue and the crown, which is the concrete cap that covers the top of the chimney. Gap usually forms in this area after a few seasons. Water entering this gap can flow all the way down the side of the flue.
- Repair cracks in large crown areas: The chimney crown is a sloping cap that forms the top of the chimney. Its purpose is both to protect the brick part of the chimney and to prevent water from collecting in the chimney. Crown cracks are more problematic than cracks in the vertical part of the chimney, as water, snow, and ice can accumulate in the chimney. Moisture remains in this area even with the recommended 1: 4 tilt ratio for the crown.
- Repair hairline cracks with sealant: Hairline cracks are sometimes called spider cracks and are treated differently than large cracks because the mineral particles in the patch or grout are too large to fit in the narrow space of the hairline crack. The solution is to use a masonry sealer with a very liquid consistency that can penetrate the cracks in the hairline.
- Fix broken bricks: Individual chimney bricks with small cracks can be repaired with hot mortar and caulking guns. Clean the cracks with the end of a putty knife or a screwdriver. Clean the cracks with a wire brush. Push the heat-resistant mortar into the crack as much as possible. In general, grout does not stretch much unless there are large cracks.
- Replace the cracked stone: Severely damaged bricks need to be completely removed and replaced. You can carefully remove one stone without affecting adjacent stones.
Slowly scrape the mortar between the bricks using a masonry chisel or an old slotted screwdriver. Drilling holes in the mortar with a drill and a masonry bit can speed up the process and even restore it. When the stone loosens, pull it out by hand. Use fleas to remove and smooth the remaining mortar from adjacent bricks.

When should you repair your chimney?
The best time to go through chimney repair service or any masonry work is after the completion of winter. At the time of winter, the cold climate affects the exteriors of brick chimney repair making it difficult to repair the property. Furthermore, chimneys are mostly used in winter so it’s important to get it repaired in spring.