A Guide to Chimney Repairs

Back in the day, fireplaces were solely used for heating. However, whether traditional, electric, or gas-fueled, fireplaces are making quite a modern comeback, especially in balancing practicality and aesthetics.

Nonetheless, a fireplace (and chimney) requires a hefty amount of maintenance compared to another, more standard heating system. Even though your grandparents were most likely seasoned professionals in all things chimney maintenance, chances are they haven’t passed down their knowledge since chimneys were fated to fizzle out of use. 

To repair a chimney, you have to, first and foremost, understand the source of the issue. Here’s a look at the possible causes and solutions to fix your chimney problem!

How to Repair a Chimney

Repairing a Smoky Fireplace

A smoky fireplace is self-explanatory; it stems from a chimney issue that results in smoke seeping out the fireplace instead of through the flue and out the vent. As such, the smoke created during combustion during a wood-burning fire isn’t dispersed via the chimney; instead, it lingers inside the fireplace and smokes your home. 

This problem can be extremely hazardous for the dwellers since these emanations are toxic. Furthermore, the smoke may stain the walls and ceiling and emit an unpleasant odour. 

A smoky fireplace is an issue that can affect all wood-burning heating systems, like open-flame fireplaces, flue-lined chimneys, as well as wood-burning stoves. Therefore, you first have to understand the source of the problem before even attempting a fix. Oftentimes, a lack of maintenance or a defective draft fan is the root cause of a smoky fireplace. 

Possible Solutions

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• Sweep the chimney (DIY using a cleaning kit or hire a professional);

• Install an anti-downdraught cowl;

• The problem can also result from improperly lighting the fire. The fire shouldn’t be lit all at once, but rather progressively. First, light pieces of paper, then add larger logs to the stack;

• If you notice the problem in question only occurs during strong winds, it may result from gusts of wind entering your chimney flue. The solution here might be to lift the ducts or install an anti-downdraught cowl.

Improve Chimney Draft

A chimney with a proper pull ultimately depends on the strength of the fireplace and its combustion chamber. It must be stable, therefore not too strong, yet not ineffective, to guarantee optimal comfort while maximizing energy savings. 

When your chimney pull is insufficient, the risks of downdraught are higher, which may lead to a buildup of soot or other deposits in the chimney and flue. As a result, your chimney will lose heat, and its use will become polluting. 

Furthermore, it increases maintenance fees and lessens the durability of the chimney equipment. The suggested solution here would be to install a draft control damper, which has multiple functions (optimizes fuel consumption, reduces pollutant emissions, facilitates maintenance, etc.).

If, on the other hand, the draft pull is too severe, there is a risk of overheating that could also damage the device, and your energy consumption will drastically increase. To fix this problem, you must install a chimney fan to improve the chimney draft pull and combustion. 

Other Chimney Care and Maintenance Solutions

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If your chimney issue concerns the lighting process, it could signify a lack of airflow from an overly effective home insulation system. The simplest solution would be to air out your home by opening a window. 

The quality of the fuel used may also be at fault. We advise avoiding using green wood since it has to be split and very dry (with a humidity level below 20%). Also, don’t overload the grid (2 kg of dry wood suffices to heat a 7 kw stove for an hour).

Repairing the Firebox

Before jumpstarting any repairs on your firebox, wait 48 hours between your last chimney fire and the repair time. After this lapse of time, you’ll need to first sweep the firebox using a rag, then with a wire brush. Doing so will make it easier for you to distinguish the damaged or broken chimney parts from the non-broken ones.

Once you’ve spotted the damaged parts, slightly wet them using a paintbrush so that the mortar you’ll apply in the next step better adheres. Once the preparatory steps have been completed, move on to step two and grab a trowel to apply a layer of mortar over any cracks in your chimney. 

Don’t forget to remove any excess mortar for a smoother surface. If you want a quick-dry mortar solution, you can light a fire a few hours after completing your repairs. 

How to Repair a Chimney Stack

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The chimney stack refers to the part of the chimney that sticks out of the roof. Any cracks on the chimney stack can lead to a less efficient draft pull. Therefore, fixing it is of utmost importance. If the issue is a leak at the base of the stack, it can be easily fixed by placing a zinc coating beneath your roofing. The coating will need to be inserted in such a way as to guarantee your chimney’s waterproofing. 

Repairs will be a little more difficult if there are leaks or water infiltration near the lintel. If the cracks are small, simply sealing off the area with a bit of plaster or a new weatherstrip will suffice. However, you will have to redo everything anew if the cracks are more significant. 

Also, the process is equally complicated if the chimney’s masonry necessitates repairs. Small fissures can be easily repaired on a concrete chimney stack by applying a waterproofing sealant. 

If your chimney stack is made with building stones, terracotta, or fire brick, contact a professional for your chimney repairs, as only a qualified professional can ascertain the root cause of the problem to later effectively repair it. In most cases, to repair large cracks, you’ll have to dismantle the stack and rebuild it from scratch. 

If you’re curious about how you can find the best contractor for your renovation project, feel free to check out our article Finding the Right Contractor for Your Renovation Project.