How to Fix a Leaking Chimney in the UK?

A leaking chimney is not just annoying but also causes damage to your house and expensive repairs. It can slowly damage your roof, walls, and even the interior of your home. Water leaking inside chimney is not due to any one reason; it can occur according to different areas and their weather conditions. But fixing it is not as difficult as it seems.
In this article, I’ll guide you through how to fix a leaking chimney, its causes and its cost. Plus, I’ll share a real-life case from Norwich, where our RBG Roofing team successfully detected and repaired a tricky chimney leak. That repair was a perfect example of how proper inspection and the right fix can save your home from damage.

Common Causes of a Leaking Chimney

Let’s discuss the possible causes of a chimney leak that occurs in every house:

Damaged Chimney Flashing

Flashing is basically a metal seal around the chimney that stops the water from coming close to the roof. If the flashing becomes cracked or loose, then water can leak in.

Old Bricks and Mortar

Bricks and mortar absorb a lot of water, and in winter, when the temperature slightly rises, the ice becomes water, and the water is absorbed into them. Some waterproofing material is not good enough and water still gets in.

Cracks in Chimney Crown

The crown is usually made of cement and is used on the top to stop the rain and snow from coming in. Cracks can occur in the crown due to shifting of the chimney structure, and through cracks, water can easily get inside.

Condensation Inside Chimney

Chimneys require a proper ventilation; otherwise, the moisture will remain inside them. And if the moisture remains inside, it obviously causes leaks. You should remember this while building a house in the UK. 

How to Fix a Leaking Chimney? Experts Guide

If you think that your chimney has a minor leak then you can follow these steps but if you don’t understand the reason for the leak and how to do it then you should hire a professional to do this job.

1- Examine the Chimney

Examine the chimney very carefully. First of all, look for any visible cracks, loose mortar or damaged flashing. Then, carefully look for water stains around the chimney area. You can also use a hose to spray water on the chimney, just to see where the leak is.

2- Fix the Flashing

If the chimney flashing is damaged or loose, then immediately replace it with the new metal sheets. Also, seal the gaps with a high-quality roofing sealant to prevent the chimney from any further leaks.

3- Repair bricks and Mortar

If the mortar is damaged, then repoint it by replacing it with a new one with the help of a chisel (tool). And if the bricks are cracked, then immediately replace them because this can cause heavy water leaks.

4- Seal the Chimney Crown

Your chimney crown should be sealed; otherwise, it has no use in the long term. Use a good quality sealant to coat the chimney crown and stop cracks from further occurring. And if a crown is damaged badly, then replace it with a new one.

5- Install Chimeny Cap

This is a very important step in this procedure. A chimney cap is used to stop rain, snow, and animals from entering inside. Also, make sure the cap is fit properly to stop water from coming inside.

6- Waterproof your Chimney

Apply a waterproof sealant to the outside of the chimney to stop the moisture damage. Make sure to choose a good sealant that is also breathable, that also allows moisture to escape while stopping water entry.

How Much Does It Cost To Repair a Chimney Leak?

The cost to repair a chimney leak in the UK depends on what’s causing the leak and how severe the damage is. On average, you can expect to pay anywhere between £150 to £700. But let’s break that down a little further so you know exactly what you might be paying for:

If the issue is minor, like repointing mortar joints, sealing a small crack, or replacing damaged flashing,  then the cost usually stays between £150 – £300. These are quick fixes that can often be done within a day.

If the leak is due to faulty lead flashing, chimney cowl damage, or damaged chimney caps, it may require a bit more work and cost £300 – £500. Labour costs also increase if scaffolding is needed.

If your chimney needs full repointing, a complete flashing replacement, or repairs to the chimney stack or crown, you might expect a higher bill up to £700. In some cases, if there’s water damage to nearby roof sections or internal walls, the costs can climb even higher.

Case Study: Fixing a Leaking Chimney in Norwich

Recently, a homeowner in Eaton, Norwich, noticed water patches on their living room wall. At first, he thought that it was just a minor condensation, but after heavy rainfall, water started leaking inside the chimney. Then, he got worried and contacted our company, RBG Roofing, for an inspection.

Inspection

When our team started the chimney inspection, they found that the metal flashing around the chimney was damaged, the mortar between the bricks was damaged, and the crown of the chimney had cracks. The homeowner became worried about the damage this leak would cause to his house. But our RBG team guided him and committed to fixing the chimney leak properly.

How RBG Roofing Fixed the Leaking Chimney?

Since the chimney flashing and mortar were damaged, the team replaced them with new ones. They also applied a sealant on the chimney crown to stop rainwater from coming inside because it had visible cracks. Also, the team guided the homeowner to do regular inspections of the chimney to prevent expensive repairs.

Results

After doing all the steps and procedures of repairing chimney, our RBG team tested everything by spraying water on the chimney and roof. And guess what? No leaks were detected! The homeowner was fully satisfied and gave a 5-star review with a good note.

“I was so worried about the water damage, but RBG Roofing did an amazing job. Now, even after heavy rain, there are no more leaks! I highly recommend them to anyone dealing with a leaking chimney.”

Conclusion

So, if you have a chimney leak, it’s important to fix it immediately to prevent further damage to your property. Whether replacing flashing, sealing cracks, or waterproofing, a proper chimney leak repair keeps your home dry and safe. If you don’t know how to fix a chimney leak, you can hire our professional RBG roofing team for an inspection and repair.

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