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A family business established in 1985

Roofing & Building Services in Essex, Hertfordshire & North London

Chimney Flashing Roof Leaks

chimney flashing roof repair
Got a leaking roof? You Might Have Problems With The Chimney Flashing

If you own your own home, you will be aware that a leaking roof presents multiple challenges. Roof leaks never occur at a convenient time and can cause significant damage to the interior of your building if not rectified immediately.  Water will get in to the smallest of places. The effects of water damage can remain long even after the repair has been done, with mould growing on the interiors of a building.

It can be difficult to find the source of a roof leak as sometimes the source of the leak on the outside of your house doesn’t actually match where the leak appears inside. If you see water stains near or above a fireplace and you’re certain your roof is not damaged, you may need to check your chimney flashing.  Chimney flashings are a common cause of roof leaks as they are notorious for letting water creep in to your home.

What is a Chimney Flashing?

Chimney Flashings are thin strips of metal installed at common weak points for leaks around a Chimney on a roof where large amounts of water run down or where absorption may occur. They are usually installed on your roof along the front edge, corners and ridges. They’re also inserted where the roof joins a dormer, around the edges of skylights and where a chimney enters the roof.

In time, these flashings can weaken – this is particularly true if you live in an area prone to lots of rain and strong winds. Poor installation or cheap materials can also cause the flashing sections to move out of place leaving your roof vulnerable. Also, the sealant and caulk that glues the flashings to the chimney can dry and crack leaving it open to water damage.

How to Determine if it is a Chimney Flashing Leak

The most effective way to check whether the cause of a leak is the chimney flashing is by running a low-pressure hose around the chimney and roof intersection.  If this is the culprit, you will see water dripping on the inside. The hosing procedure should be done by two people as you need one in the loft and the other using the hose, using mobile phones to communicate what is happening. Any presence of water inside the house means that you need to get your roof flashing repaired.  Be careful when using ladders and standing on a roof – wear a safety harness!  If in doubt, hire a professional.

When to Replace Chimney Flashing

Ideally, your chimney flashing should be inspected every 6 months. By regularly checking your roof, you can prevent water leaks from causing damage to your home. Typical reasons that may mean you should replace your flashing include old flashing, missing flashing, rusty flashing and separation of the flashing from your roof. When replacing roof shingles (if you have these), you should have new flashing installed to ensure that it lasts as long as your new roof.

How to Repair Loose Chimney Flashings

If you just need to replace the sealant, you do not need to hire a professional – you can caulk it yourself, assuming you take the necessary safety steps.

Here are some DIY tips:

  1. Remove any leaves or other debris that may be in the gap between the flashing and the chimney
  2. Scrape away any remaining caulk that may have hardened using a chisel
  3. Apply some cement behind the flashing
  4. Attach the flashing tight against the chimney using masonry nails or screws
  5. Apply cement over any exposed nails or screws
  6. Apply roofing to the joint between the flashing and any brick
  7. Smooth over the cement with a putty knife

Chimney flash leaks can be challenging to repair and should only be done yourself if you are confident. If you’ve redone your flashing and your roof is still leaking, you may need to seek professional help. Lethbridge Roofing Ltd can inspect your roof and repair the chimney flashing. The benefit of hiring a certified roofing contractor is that they can quickly and correctly identify any problem with your chimney flashing no matter how small.  You get efficient and quality work without the risks you face by trying it alone. 

If you need any help with identifying and repairs chimney flashing leaks, get in touch now.



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