Best Chimney Flashing Sealer (Buyer’s Guide)

There is nothing worse than coming home to find water damage in your house. It can be caused by a number of things, but one of the most common culprits is chimney leaks. If you have an old fireplace or chimney, make sure it’s properly sealed with a quality sealant and caulking before winter sets in. This buyer’s guide will help you select the best type of flashing sealer for your needs.

Best Choice

Chimney Rx Elastomeric 1/2 Gallon
  • Stops Leaks Around Chimney Flashings, Skylights, Stacks, & Vents
  • Remains Permanently Flexible to Stop Chimney Leaks
  • Easy Brush-On Application (Brush Not Included)
  • Ready to Use, No Mixing Required, Cleanup With Soap & Water
  • 1/2 Gallon Covers 14 Sq. Ft.

Chimney Rx Chimney Flashing Sealer can be used with a wide range of substrates such as metal flashing and vinyl siding in addition to most common roofing materials, concrete masonry units and stucco. It is easy to apply with a caulking gun or a brush & roller so you won’t need any special skills for the job.

Best Selling Chimney Flashing Sealer

When you are considering investing in a chimney flashing sealer, it is important to know what is available on the market. This buyer’s guide will cover the different types of sealers and give some helpful information for how to choose one that best fits your needs. Before we get into sealing your chimney, let’s take a closer look at this handy tool.

There are two main types of chimney flashing sealers: roll-on-type and spray-on type. Roll-ons are most often used by professionals who work on multiple houses or buildings each day because they offer more control over where the product goes when applying it. Spray-ons can be applied with one hand while holding onto a laddern and are easier to apply.

Best No. 1
MasonryDefender Chimney Flashing Sealer - Flexible Coating That Protects Chimney Flashings from Water Leaks
  • Seals & Waterproofs Chimney Flashings - Stops Water Penetration Where Chimneys Meet the Roof Line
  • Flexible - Won't Crack or Chip - Stays Flexible Over Time, Doesn't Harden and Become Brittle
  • Helps Prevent Chimney Leaks - Chimneys Frequently Leak Where the Roofline Meets the Chimney - Seal...
  • Easy to Apply With a Paint Brush - Simply Paint Product Around Base of Chimney for Long Lasting...
  • Available in Black & Covers 14 Sq. Ft. Per Half Gallon Container
SaleBest No. 2
FlashSeal Elastomeric Flashing Sealant, 1 Gallon (Black)
  • 7 Year Warranty (When Used With FlashSeal Fabric, Sold Separately)
  • Stops Leaks From Flashings Around Chimneys, Stacks, Vents, & Skylights
  • Easy Brush Application (Brush Not Included), Soap & Water Cleanup
  • Significantly Outlasts Tar-Based Sealers
  • 1 Gallon Size Covers 28 Sq. Ft.
Best No. 3
Chimney Rx Elastomeric 1/2 Gallon
  • Stops Leaks Around Chimney Flashings, Skylights, Stacks, & Vents
  • Remains Permanently Flexible to Stop Chimney Leaks
  • Easy Brush-On Application (Brush Not Included)
  • Ready to Use, No Mixing Required, Cleanup With Soap & Water
  • 1/2 Gallon Covers 14 Sq. Ft.

Chimney Rx Chimney Flashing Sealer

Chimney Rx Elastomeric 1/2 Gallon
  • Stops Leaks Around Chimney Flashings, Skylights, Stacks, & Vents
  • Remains Permanently Flexible to Stop Chimney Leaks
  • Easy Brush-On Application (Brush Not Included)
  • Ready to Use, No Mixing Required, Cleanup With Soap & Water
  • 1/2 Gallon Covers 14 Sq. Ft.

Product Description

The Chimney Rx Chimney Flashing Sealer is a 100% solids, elastomeric silicone sealant that provides exceptional watertightness and long-term durability. This product mimics the chemical structure of rubber to provide flexibility in both hot & cold weather conditions thus extending its lifespan by decades. It’s black color helps it blend into the roofing material so it is hardly visible. Since the silicone rubber doesn’t have any solvents, there are no harmful vapors that could affect your health or the environment.

Chimney Rx Chimney Flashing Sealer can be used with a wide range of substrates such as metal flashing and vinyl siding in addition to most common roofing materials, concrete masonry units and stucco. It is easy to apply with a caulking gun or a brush & roller so you won’t need any special skills for the job.

While this product can be used in most applications around your home it’s recommended that you use an acrylic roof coating on top of it since silicone doesn’t stick to asphalt shingles.

To get the best results, you should clean your surface before applying this product & let it cure for at least 24-48 hours prior to exposing it to moisture or freezing conditions. For added protection use an additional layer of acrylic roof coating on top of Chimney Rx Chimney Flashing Sealer in any areas where you want to prevent leaks.

Pros

  • Easy to apply without special skills.
  • 100% solids so it won’t shrink or crack over time.
  • Watertight seal that prevents moisture infiltration through roof flashings, skylights, stacks & vents for decades.
  • Black color blends in with the roofing material.

Cons

  • None.

Recommended?

Yes. As you can see, this product is highly recommended by many homeowners who used it on their roofs to seal around chimneys and skylights. Some of them even said that they were able to stop roof leaks after using Chimney Rx Sealer for only a few minutes while some needed several hours or days before seeing the best results.

See also
Is A Gas Fireplace Worth It?

MasonryDefender Chimney Flashing Sealer

MasonryDefender Chimney Flashing Sealer - Flexible Coating That Protects Chimney Flashings from Water Leaks
  • Seals & Waterproofs Chimney Flashings - Stops Water Penetration Where Chimneys Meet the Roof Line
  • Flexible - Won't Crack or Chip - Stays Flexible Over Time, Doesn't Harden and Become Brittle
  • Helps Prevent Chimney Leaks - Chimneys Frequently Leak Where the Roofline Meets the Chimney - Seal...
  • Easy to Apply With a Paint Brush - Simply Paint Product Around Base of Chimney for Long Lasting...
  • Available in Black & Covers 14 Sq. Ft. Per Half Gallon Container

Product Description

MasonryDefender is a spray-on coating that can be used on all types of masonry surfaces, including metal flashing and chimneys. It’s the best way to seal out water from your home or business.

The formula will work through frosting weather, so you don’t have to worry about applying it during cold temperatures. MasonryDefender is a very easy product to apply, and it can be used on any masonry surface indoors or outdoors. It’s non-toxic and safe for children, pets, plants, and the environment.

MasonryDefender Chimney Flashing Sealer will make your chimneys more efficient by keeping out cold drafts from entering your home. This will help to reduce the amount of condensation inside, which can cause mold and mildew growth.

MasonryDefender Chimney Flashing Sealer is a great way to save money on heating bills this winter by keeping chimneys from leaking heat out into the attic or living spaces.

The flexible coating sticks tightly to surfaces and will never crack, fade, flake or peel. It is designed to last for years with little maintenance required to ensure a long-lasting seal against cold drafts and leaks.

Pros

  • Flexible formula is easy to apply and will stick tightly to surfaces.
  • Lasts for years with little maintenance required.
  • Safe on all masonry surfaces indoors or outdoors, including metal flashing and chimneys.

Cons

  • Coverage is barely enough for a standard chimney.
  • Not the best value on the market.

Recommended?

MasonryDefender Chimney Flashing Sealer is a great way to seal out water leaks and drafts from your chimneys. The formula will work through frosting weather, so you don’t have to worry about applying it during cold temperatures. It’s the best way to save money on heating bills this winter by keeping chimneys from leaking heat out into the attic or living spaces. It’s a very easy product to apply, and it can be used on any masonry surface indoors or outdoors.

ChimneySaver FlashSeal Chimney Flashing Sealer

Sale
FlashSeal Elastomeric Flashing Sealant, 1 Gallon (Black)
  • 7 Year Warranty (When Used With FlashSeal Fabric, Sold Separately)
  • Stops Leaks From Flashings Around Chimneys, Stacks, Vents, & Skylights
  • Easy Brush Application (Brush Not Included), Soap & Water Cleanup
  • Significantly Outlasts Tar-Based Sealers
  • 1 Gallon Size Covers 28 Sq. Ft.

Product Description

The next generation of high-performance roofing sealant. ChimneySaver’s advanced technology ensures a durable, watertight and flexible flashing system that won’t crack or shrink. It can be used for new construction as well as re-roofing applications on flat roofs, low slope roofs (maximum of three inches), and vertical surfaces.

Pros

  • Waterproofs, protects and preserves any roofing material.
  • Seals out water penetration, air infiltration and moisture vapor transmission for roofs of concrete, clay tile or metal.
  • Designed to seal at temperatures as low as -50°F (-45°C).
  • Provides excellent adhesion with little surface preparation.
  • Designed to flex and stretch over time while remaining waterproof.
  • 100% elastomeric rubber formula won’t crack or shrink like traditional sealers, therefore reducing the need for reapplication in the future.
  • Flexible enough to move with roof expansion and contraction caused by temperature variations throughout seasons of the year.

Cons

  • Use indoors only.
  • Cannot be applied in a shaded area or when rain is expected within 24 hours of application.
  • Suitable for roofing materials such as concrete, clay tile and metal roofs which have been primed with an acrylic primer previously. It cannot be used on EPDM rubber surfaces without first priming with an acrylic surface.

Recommended?

ChimneySaver FlashSeal is a high-performance elastomeric product specifically designed for roofing systems. The next generation in roof sealants, its advanced technology ensures a durable and flexible flashing system that won’t crack or shrink.

Roll-on sealers come in a variety of colors so that you can maintain the look of your home while sealing any leaks. Spray-ons, however, tend to be more expensive and less effective than roll-ons because they cannot get into tight spaces like cracks between bricks or mortar joints as easily as their roll-on counterparts.

Now that you know what is available, let’s take a look at how to choose the best chimney flashing sealer for your needs. When choosing between roll-ons and spray-ons, think about how much work you are willing to do yourself versus hiring out the job or calling in professionals who will apply the sealant for you. If it is a one-time job, roll-ons are best because they can be applied in less time. Spray-on chimney flashing sealers require more preparation work before they can be used to prevent them from drying up too quickly and requiring another application within just a few months of use.

See also
How to Fix Roof Leak Around Chimney (User’s Guide)

What is a Chimney Flashing Sealer?

A chimney flashing sealer is a tough, flexible material that can be used for several purposes. It’s often applied to the seams of different types of roofing materials, from shingles and tiles all the way up to metal roofs. This stops moisture from getting in through gaps between individual pieces or sections on your roof, ensuring it stays in good condition for longer. Many people also use it to seal up cracks and gaps around chimneys, preventing both air leakage and water from entering through the roof or walls of their home.

In essence, a top-quality one can help you keep your property dryer with less wear on its materials—which will ultimately save money. If you’re interested in learning more about how it works and what types there are, keep on reading.

Types of Chimney Flashing Sealers

There are four major types of sealants for chimneys: mastic, polyurethane caulk, high-temperature caulking and liquid flashing. Mastic is a goopy material that can be messy to work with but makes up for it in durability. Polyurethane caulk is the most popular type and creates an airtight seal. High-temperature caulking is used for metal chimneys and ovens; it’s resistant to heat up to 500 degrees, but becomes brittle in cold weather starts cracking when the temperature dips below freezing. Liquid flashing seals around bricks like mastic with less mess than caulk or mortar mixes, but can’t be applied on top of existing sealants.

  • Mastic: goopy material that can be messy to work with but makes up for it in durability.
  • Polyurethane caulk: the most popular type and creates an airtight seal.
  • High-temperature caulking is used for metal chimneys and ovens; it’s resistant to heat up to 500 degrees, but becomes brittle in cold weather starts cracking when the temperature dips below freezing.
  • Liquid flashing seals around bricks like mastic with less mess than caulk or mortar mixes, but can’t be applied on top of existing sealants.

Benefits of using a Chimney Flashing Sealer

When you are looking to buy a chimney flashing sealer, there are many benefits associated with them. A number of the top reasons that people choose this product include:

  • They help improve efficiency in your home.
  • Perhaps one of the biggest benefits is that they actually make it easier for heat to be used in homes by increasing their energy efficiency.
  • They help you save money on your energy costs.
  • This is due to the fact that they make it easier for heat to be used in homes, which improves how much of the heating elements get utilized by people living inside of them.
  • A number of homeowners find that using this product actually makes their home more comfortable to live in.

How to use the best Chimney Flashing Sealer?

The first thing you need to do with your chimney is clean it. This can be done by using a pressure washer or climbing up on the roof yourself and scrubbing the brick work down with some soapy water. Once this has been completed, allow it to dry before applying any sealant.

  • Now that you have cleaned the brick work, it’s time to apply your sealant. For this you will need a brush that has stiff bristles and is capable of applying the sealer where necessary.
  • It should take about half an hour for the chimney flashing sealant to harden completely before you can safely walk on top of it without fear of slipping or falling.
  • As long as you have cleaned the brick work properly, this is a very simple process that will only take about half an hour from start to finish.
  • The chimney flashing sealant should be applied in a thin even coat and allow it to dry for between 30 minutes and one hour before walking on top of it. This means you should not apply to the chimney until after you have cleaned it.
  • You should avoid applying sealant in direct sunlight as this will make the drying process take longer than usual and increase your risk of slipping or falling on top of it.

Common questions about Chimney Flashing Sealers

What is a chimney flashing?

Chimneys are built with specific materials and standards, but the most common material used for this part of your home is brick. Chimney flue tiles have been made from clay or concrete since the early days of homes being heated by fireplaces. The modern chimney tile has evolved to include a steel reinforcement to increase the life expectancy of these products. The mortar that holds them in place is called flashing and it protects the overall structure from exterior elements such as water, wind, and ice. Over time chimneys can develop cracks and leaks which allow moisture into your home’s walls and insulation. This causes damage over time, increasing heating costs and decreasing your comfort levels.

What is a chimney flashing sealer?

A flashing sealant, also known as high temperature caulk, can help to stop water from entering the inside of your home through these cracks and crevices around the flue tiles. Without this protection, moisture gathers between the brick or stone structure and the mortar. Over time, this can cause severe issues with water damage and mold growth that will need to be addressed by a professional home inspector.

See also
How to install a Chimney Damper?

What are the different types of chimney sealants?

There are many kinds of flashing sealant on the market today but most fall into two categories: silicone or acrylic based products. Silicone is the most popular choice because of its long-lasting durability and resistance to extreme temperatures. However, it can be difficult to find a silicone product that will work on metal flashing surfaces. Acrylic sealants are easier to apply but do not have as much range for expansion or contraction without cracking over time.

How does a chimney sealer work?

Sealants for chimneys typically feature a high-temperature version of the material to protect against extreme weather fluctuations. These products need to be able to withstand temperatures as low as -40 degrees Fahrenheit and up to 500 degrees Fahrenheit depending on your local climate conditions. This sealant is applied by using an applicator tube that is available in most hardware stores. The sealer is squeezed out of the tube and onto an area along the edge of your chimney brick or stone where it will be exposed to water penetration.

What does a Chimney Flashing Sealant do?

A flashing sealant creates a barrier between interior and exterior elements by filling in any cracks or crevices that may have formed around the flue tiles. Over time, these cracks can lead to water damage, mold growth and energy loss in your home’s walls.

What are some benefits of using a chimney flashing sealant?

Sealants for metal chimneys are often easier to apply than other types because they are typically designed to be troweled onto the surface of the metal. This allows you to create an even seal with just your hands or a putty knife, rather than having to purchase special tools for this job.

Environmental Protection

Chimneys are designed to work properly for many years. However, the flashing will wear down over time and it is important that you replace this flashing on a regular basis. Failure to do so could result in water leakage into your chimney which can cause extensive damage to your chimney and even result in a dangerous situation.

The manufacturers of this sealer have made it to be used on many surfaces such as concrete, wood, metal etc. Given that you can use it with confidence knowing that the product is designed for all types of flashing materials makes this an ideal choice for homeowners who are not familiar with what the right product to use is.

This sealant will not only ensure that your chimney flashing lasts a long time, but it also protects against rust and corrosion which could lead to bigger problems down the road. This makes this option by far one of the best you can find on the market today!

Safety Tips

  • Make sure you are using a ladder that can reach the roof. You should not be on anything less than this height, so keep your safety in mind!
  • Never work alone if it is possible to avoid doing so. Call for help if something goes wrong and do not use ladders or scaffolds unless they were designed for this purpose.
  • Make sure that the area around your chimney has been cleaned up before you do anything else. This will help to reduce any dangers of falling objects or slipping hazards, which could cause an accident for yourself and others.
  • As with any home repair, cleaning or work you are doing that could potentially cause a hazard for yourself or others, it is best to put on the appropriate safety equipment as well. Things like gloves and hardhats can be purchased at your local hardware store if needed!
  • As with any home repair, cleaning or work you are doing that could potentially cause a hazard for yourself or others, it is best to put on the appropriate safety equipment as well. Things like gloves and hardhats can be purchased at your local hardware store if needed!
Chimney Rx Elastomeric 1/2 Gallon
  • Stops Leaks Around Chimney Flashings, Skylights, Stacks, & Vents
  • Remains Permanently Flexible to Stop Chimney Leaks
  • Easy Brush-On Application (Brush Not Included)
  • Ready to Use, No Mixing Required, Cleanup With Soap & Water
  • 1/2 Gallon Covers 14 Sq. Ft.

FAQs

What are the different types of chimney flashing?

There are three main chimney flashings: metal, clay/tile and rubber. Metal is used in steel or copper roofs that have a slope to allow water drainage. Clay tile is made from fired earth products while rubber flashings are flexible materials typically created for lightweight building structures.

What is a flashing kit?

Flashing kits help you seal the joints and seams of your chimney, but they’re also very helpful for roofs. Flashing kits are easy to use – simply cut them into pieces that fit over each joint or seam then cover it with caulk. You can even paint flashing kits to match the roof.

How do you apply flashing?

Flashing is simple to install. Most manufacturers of chimney flashings suggest using a paper tape, which provides an airtight seal between two materials without damaging them with chemicals or solvents. You can also use mastic for professional-grade results on single ply membranes.

What are the benefits of chimney flashing?

Chimneys that don’t have any kind of flashing or sealant can allow water to seep into cracks and fissures in the brick, mortar joints and even between bricks. This can cause severe damage down the line, so it’s important to have a good chimney flashing in place.

What is the best way to find a contractor?

The first thing you need to do when your roof needs repair or replacement, especially if it’s been damaged by water damage from bad weather conditions, is research local contractors and solicit quotes. Try asking family members for referrals, or check online for reviews from previous customers.

What are some tips to keep my roof in good condition?

Keeping your roof clean and free of debris is a great way to prevent damage, but even roofs that aren’t dirty can be invaded by molds and mildews if not properly maintained. Regularly clearing out gutters and downspouts is a must, but you should also have your roof pressure cleaned every few years to remove dirt, moss and other harmful buildups.

What will happen if I don’t maintain my roof?

If left unattended for too long, damage from weather conditions can get out of control quickly on a roof. If you neglect a leaking or damaged roof long enough, it can cause serious damage to your home and will likely require repairs that are much more expensive than preventative maintenance would have been in the first place.

Do all roofs need flashing?

As we mentioned above, most homes with chimneys also benefit from having some type of chimney flashing. However, even homes without their own chimneys can benefit from the installation of a roofing system that incorporates flashings and sealants.

Conclusion

There are a lot of chimney flashing sealers that you can use, but the best one is Flashing Seal. It will provide waterproofing for up to 50 years which makes it well worth your money and time. You should definitely try out this product instead of wasting money on other inferior solutions!