Leaking chimneys can be expensive to repair. Chimney damage when ignored can cause structural and more expensive damage, so you are better fixing problems as soon as they are found. In most cases, a chimney starts leaking as the result of faulty flashing and this can be easily repaired. The flashing is the metal sheet that is installed to make sure the connection between the chimney and your roof is watertight. Over time and wear, can flashing can become less effective. To avoid any potential issues with flashing you should get your chimney inspected every year.

Chimney Flashing Leaks

Flashing Installation

Understanding the installation of flashing is important to understanding how it works. Knowing the process can also help you make sure your flashing and chimney have been correctly installed. Flashing consists of two metal panel parts. The first (step or base flashing) is installed under a shingle and is then bent upwards to meet the chimney. Holes and cracks are the most common issues with this part of the flashing. The second part is counter flashing and this is bent over the first part. Counter flashing is embedded into a chimney mortar joint and seals off the top portion of the step flashing below.

Flashing installation can be a challenge because corners are vulnerable areas in roofing. Even when high-quality and professional installation done, there is always a weak spot that needs to be addressed. Quality urethane caulking should be applied to the flashing to make sure it is waterproof. Leaking at corners and weak spots that is allowed to continue can damage this caulking, so it should be regularly checked and reapplied when needed. Caulking cannot fix flashing materials that are not properly overlapped and this will require new installation instead.

Flashing materials vary depending on the region and type of metal used. Galvanized steel and aluminum are the most popular choices and are the most affordable. Copper is used for higher-end installations because it is more durable and the corners form a stronger watertight connection. Copper can be soldered where other metals cannot allowing for tighter connections. The type of metal used for flashing is not as important as the installation techniques. Correct layering is essential to the waterproofing capabilities of the flashing.

Replacing Chimney Flashing

Leaking around the chimney may not always be evident right away but if left, can cause serious and expensive structural damage. If moisture is allowed through the roof, the ceiling areas can become damaged by rot and the walls and attic spaces can be weakened structurally too. Chimneys and the flashing need to be inspected every six months to a year, to make sure any damage is taken care of right away.


We will conduct thorough inspections of your chimney to identify weak spots that are at risk for moisture problems. We use crickets during installation to ensure that the flashing will work effectively. Crickets are triangle-shaped diversions that are built behind the chimney at the roofline. Call us today for an inspection, or flashing repair that you may need.


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