11 Signs You Need to Replace Your Chimney Flashing

Installation of new chimney copper flashing

It’s easy to overlook your chimney flashing – after all, it’s a tiny part of your roof system, and you can’t even see it from the ground. But this seemingly unimportant element plays a key role in keeping water out of your home.

The smallest issue with your chimney flashing could impact not just the safety of your family but the structural integrity of your living space. Learn about the 11 signs for replacing your chimney flashing to avoid water damage and other serious problems in your home.

What Is Chimney Flashing and Why Is It Important?

Blue chimney flashing
Photo Credit: Jupiterimages / Canva Pro / License

Chimney flashing is a metal sheet found at the meeting point between your chimney and roof. It creates a watertight seal that protects against water penetration and moisture damage. Chimney flashing might not cross your mind very often, but if it’s been a few years since you last performed a thorough roof inspection, now may be a good time to check it out. 

Properly installed and maintained flashing can last up to 30 years – on the condition that you check it periodically and repair any damage as soon as it appears. If it’s damaged, it must be repaired to protect your chimney and the inside of your home.

Chimney flashing is an essential part of a chimney system. It wraps around the chimney and extends to the roof, adjusting differences in inclination and pitch to stop water from leaking into your home. By installing chimney flashing, you’ll successfully avoid:

  • Discoloration
  • Water leaks
  • Water stains
  • Decay
  • Rust
  • Mold
  • Collapse

11 Signs You Need To Replace Your Chimney Flashing

All parts of a home are vulnerable to the passage of time – and chimney flashing is no exception to this rule. It can become damaged over time, allowing water to penetrate your home. Flashing failure usually occurs due to faulty installation, but Mother Nature will also take a toll on your chimney protection system with heavy rain, snow, ice, hail, and winds. Let’s dive into the biggest signs your flashing may need repairs or replacement.

Leaky Chimney

If you see water dripping from your chimney or moisture forming around it, you’ll need to address it immediately. Chimney leaks will allow water to penetrate your roof and reach your interior walls, causing mold formation and health risks.

Flaking Chimney Tiles

Every once in a while, take a close look at the base of your fireplace. If you notice chimney tile flakes, it could mean your chimney liner has been damaged. In such a case, replacing it will prevent a mix of the gasses inside and the air outside, which can be a serious fire hazard.

Damaged Chimney Mortar Joints

Remember to check your chimney’s mortar joints during your roofing and chimney inspections. Their role is to keep the chimney in place and secure. If you notice damp mortar joints, this is likely due to constant exposure to rainfall, ice, snow, and seasonal humidity. Damaged mortar joints won’t be able to support your chimney.

Cracked Chimney Crown

The chimney crown plays a significant role – it protects your chimney’s structure from Mother Nature. If your chimney crown is cracked, water will seep into your chimney, the masonry surrounding it, your walls, and eventually your home. This issue also allows insects and other pests to enter your living space.

Deteriorated Chimney Brickwork

The integrity of the bricks that hold your chimney together is vital. Check for signs of peeling, loosening, crumbling, or flaking, which indicates damage that should immediately be addressed by a professional contractor.

Signs of Corrosion

Should you notice rust stains around your chimney flashing, be sure to give your local roofing contractor a call. Chimney flashing repair should always be performed as soon as possible to avoid further damage.

Compromised Caulking

Dry, rotted, or peeling caulking may indicate a need for chimney flashing repair or replacement. If ignored, the flashing can separate completely and allow water to penetrate your home.

Water Stains on the Ceiling Near the Chimney

Anytime you notice condensation, dripping, or water stains inside your home, the root cause should be addressed immediately. If the damage is near the chimney, it usually means that your flashing needs repairs. Don’t forget about your ceiling and roof, which have also likely been damaged and require attention.

Puddles in the Firebox

Water in your firebox can be a cause for concern. Carefully inspect your chimney system and identify the cause, which could include faulty flashing. Contact a roofing professional if you’re unfamiliar with the ins and outs of chimneys.

Discolored Brickwork

A clear sign of a water problem is brick discoloration, also called efflorescence. What this means is that the masonry has experienced prolonged exposure to moisture, which is drawing out soluble solutions from the brickwork. Once they evaporate, you’re left with white salt stains. Essentially, any color that doesn’t match your brick, such as black, brown, white, or green, indicates a bigger issue that is contained and should be fixed right away.

Musty Smell

The smell of mold or mildew coming from your chimney means there are chimney leaks, and the flashing is likely compromised. More than that, it usually indicates a problem that has been present long enough for bacteria and fungi to grow.

Types of Chimney Flashing

Different types of chimney flashing are used depending on the size of your chimney and the style of your home. When combined with caulk, flashing provides a waterproof seal. We provide an overview of the 5 most common types according to their particular uses.

  • Step flashing is the most common and easy-to-install type of flashing used on residential homes, suitable for most chimney shapes and sizes. 
  • Apron or continuous flashing is installed along the base of the chimney, but unlike step flashing, a long piece of sheet metal is bent to perfectly fit the chimney and roof. It costs more than step flashing and is best used on larger chimneys in areas with heavy rainfall.
  • Counter flashing protects the base of the chimney at the meeting point with the roof. It goes over the step or continuous flashing and extends down the walls of the chimney. 
  • Cap flashing is generally made of metal and placed around the chimney flue to block water from entering the chimney. It’s especially useful in mitigating water damage in heavy snow or rainfall areas.
  • Cricket flashing is used for bulkier chimneys that are regularly exposed to pooling water on the roof. A cricket is a triangle-shaped structure built behind the chimney to direct water away from the chimney; after construction, it is wrapped in flashing.

Chimney Flashing Materials

If you’re in the market for new chimney flashing, there are a few flashing materials to choose from. Here are the most common flashing types found on the market.

Aluminum: Aluminum is a popular choice among homeowners due to its low price point and ease of installation on any type of roof. Aluminum is also quite resistant to rust, which makes a difference long-term.

Metal: Steel is likewise commonly used to manufacture chimney flashing. It’s not only durable, but it has excellent anti-rust properties.

Copper: Copper is the obvious yet more expensive choice if you want durability, nice curb appeal, and a lightweight material. Copper also never rusts and can withstand difficult weather conditions.

Lead: Lead flashing is a supple and malleable material typically used on homes in the northern part of the country. While many homeowners are wary of lead flashing due to its toxic nature, the right contractor can easily use it to create a watertight seal.

Vinyl or PVC: Vinyl or PVC chimney flashing has grown in popularity because it offers similar benefits to metal flashing minus a complicated installation process. The downside? It lacks durability and resistance to extreme weather conditions.

Cost of Replacing Your Chimney Flashing

Lead flashing repairs
Photo Credit: DrewRawcliffe / Canva Pro / License

If you detect leaks around your chimney area, especially in the attic insulation or on your ceiling or walls, missing or damaged chimney flashing could be the cause – which is why a replacement could be in order.

Professional Installation

On average, you can expect to pay anywhere from $250 to $1,400 for professional chimney flashing replacement. This price will depend on:

  • Your chimney size and type
  • The flashing you choose
  • Your roof type
  • The labor hours needed

When it comes to professional installation, also consider the following:

  • If you have a metal chimney and a stainless steel flue duct, you’ll pay between $300 and $600 to flash the exterior of the chimney.
  • If you have a brick or stone chimney, replacing the flashing will likely fall in the $500 to $1,500 range. For a large chimney with multi-flue ducts, the price can easily reach $1,000.
  • Customized flashing manufactured to match your roofing material will cost more.
  • You’ll need to budget for cleaning costs, inspection costs, and other chimney services.

DIY Installation

You’ll typically pay between $65 and $100 for a DIY job. But while this may be the more budget-friendly option, there are other considerations to remember:

  • Safety precautions Once you access your roof, some 30 feet above the ground, avoid falling or injuring yourself when handling the metal sheet pieces. Don’t start the job without appropriate safety equipment.
  • Experience – For a DIY project, you must know how to accurately measure the angles of your chimney and roof as well as nail, seal, and caulk the chimney flashing.
  • Materials and tools – You’ll need the proper materials and tools to complete a flashing repair or replacement job. 
  • Time and working conditions – When it comes to chimney flashing, work should start in the early morning before the sun has had a chance to bake your roof. The heat can be a problem if you’re not used to spending a lot of time working outside.

FAQ About Chimney Flashing

Does homeowners’ insurance cover chimney leaks?

Homeowners’ insurance covers chimney repairs or replacements if they were caused by an event such as a fire or lightning strike. Chimneys that become damaged due to age are typically not covered.

Which chimney flashing type is best?

When it comes to durability, the type of flashing you choose is very important. Copper is by far the most durable flashing material on the market. It is the highest quality but also costs more than other types. While aluminum is a good middle-of-the-road option, PVC or vinyl cost less if you’re on a tighter budget.

What color should my chimney flashing be?

Most homeowners choose black or natural brown flashing due to its neutral appearance. Silver (or bare) flashing is also available as a cost-effective option, though this type can look overly bright and create an unpleasant glare.

Get Expert Help

Roofing and chimney issues can be stressful, so being able to turn to a reliable professional is key. We can connect you with a top-rated roofing contractor to help your chimney project run smoothly and meet all your chimney flashing needs.

Main Photo Credit: English: NPS Photo / Wikimedia Commons / Public domain

Andie Ioo

In my free time, I enjoy traveling with my husband, sports, trying out new recipes, reading, and watching reruns of '90s TV shows. As a way to relax and decompress, I enjoy landscaping around my little yard and DIY home projects.