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How to repair a leaking chimney stack

Repairing a leaking chimney stack should only be done by licensed professional chimney service providers. Leaks from your chimney may be a significant source of worry for homeowners. Chimney inspections should be undertaken at least once a year for this reason. These inspections allow for the early detection of probable chimney damage and avoid costs. Many homeowners who have chimneys in their homes are unconscious of their presence.

Long-term degradation of the chimney can cause structural damage to the chimney, the home, or fire dangers; this is not a good safety practice. Water leaking is a common cause of chimney degradation. Water-damaged chimneys can result in liner deterioration and flue obstruction. It is advised that when completing periodic house inspection checks, you check for chimney leaking stacks, and if a problem arises, hire a qualified professional who can repair a leaking chimney stack.

Signs of a leaking chimney stack

You should be aware of the several indicators of a leaky chimney stack. They include:


Chimney flashing leaks:

It is common practice to apply chimney flashing to the base level of the chimney, where the stack meets the roof structure. Chimney flashing is often installed at the chimney base, where the stack meets the roof structure.

It functions as an agent over various roof sections to guarantee that the brickwork is watertight.

Gaps will form between the bricks when the chimney is used more frequently for various reasons, including improper chimney flashing and stack repairs, among others.

Water leaking and penetration into the chimney due to a breach without sufficient flashing can cause severe damage.

Chimney flashing materials provide temporary protection from chimney stacks. However, long-term usage is not suggested since time promotes deterioration, exposing the chimney to gaps or cracks.


Brick and mortar leaks:

Bricks and mortar are not entirely resistant to water. When water leaks into the chimney and accumulates over time, bricks and mortar surrounding it deteriorates.

This is a significant sign of chimney leaks, and it is critical to address the problem before it worsens and jeopardizes your chimney’s safety.

All bricks and masonry, including chimneys, will degrade with time due to water’s long-term impacts.

Water can seep through the bricks when the chimney stack fractures and falters, causing damp and leaking.


Chimney crown cracks:

A chimney crown’s purpose is to keep wintery elements out of the chimney and brickwork. Water leakage into the chimney can be caused by a break in the crown, reducing the chimney’s lifespan.

To avoid such circumstances, it’s critical to ensure that the chimney is maintained and inspected regularly.

Early discovery of cracks in the chimney crown allows you to treat and repair them with a suitable sealant, extending the chimney’s life.

How to repair a chimney stack

  • For weatherproofing the chimney, it is advised that you use long-lasting and sturdy lead.
  • If the chimney stacks and roof have deteriorated or have faults, the damaged components should be removed and rebuilt with new flashings to extend the chimney’s lifespan.
  • Avoid the lesser brands of glass-reinforced plastics since they might harm the chimney.
  • If water leakage persists after the flashing has been put in, check to verify if the flashing installed is the correct fit. If it isn’t, it should be fixed right away.

Leaking chimney stack: Cost of repairs

For minor chimney repairs, such as flash fix, tiles, brick, and mortar, it ranges between $200 – $700. For major repairs, such as chimney stacks, replacement of crown, spalling of breaks, etc., it ranges between $1,000 – $3,500. The following are estimates for various chimney leak repair costs:

Chimney leak Cost
Repair of leaning chimney stack $2,000 – $4,000
Removal of chimney stack $800 – $2,000
Rebuilding of chimney stack $1,000 – $3,500
Replacement of a chimney stack $4,000 – $15,000
Replacement of masonry chimney with chimney stack $6,000 – $18,000
Cost of chimney stack repoint $500 – $2,500
Repair of a leaking chimney $150 – $400
Waterproofing/sealing $150 – $400
Cost of flashing repair $200 – $500
Cost of flashing replacement $300 – $1,500
Cricket installation $200 – $1,000



The brick or stone segment of a chimney that sits high above the building’s roof is known as a chimney stack.
 A chimney is the whole structure that is located on the rooftop of a building. A chimney stack is a specific part of the chimney.
 Chimney stack inspection is recommended at least once a year to ensure optimum performance of the chimney and its components.
Yes, it can. A chimney stack built without the necessary support can collapse, which is very dangerous to the house and homeowners.

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