Best Flashing for Brick Chimney (2026)

Compare the picks

Specifications are manufacturer stated, as published on each listing and collected 21 October 2026. Warranty terms below are as stated.

Why brick chimneys are picky

Brick moves with heat and frost while the roof deck moves differently, so the joint between them works constantly. That is why the listings stress flexibility: both sealants promise to stay flexible instead of cracking, and the boots allow for expansion, contraction and pipe vibration. A rigid patch, however neat, opens back up with the first freeze-thaw cycle.

Mortar is the other half of the joint. Sealant bonds to sound brick and mortar; it does not fix spalling brick or missing mortar. If the chimney crown is cracked or the mortar joints are hollow, repoint first and seal after. The sealant is the raincoat, not the structure.

How we scored them

Each product is scored on performance, build, value, safety and warranty, with the weights published on our How We Pick page. Performance weighs fit for a brick chimney and stated coverage; a stated warranty earns warranty points.

Scores run from 9.2 to 9.8: each product’s point total is placed on that range, so more points always means a higher score. Safety counts only for powered gear or where the listing states safety features; where it does not apply, the score is taken over the remaining 90 points.

What the listings tell you

We read five chimney flashing listings: two brush-on sealants and three silicone pipe boots. Only two state a warranty term (ChimneySaver 7 years with fabric, Sobalai 2 years). None states a safety certification, so safety scores are zero across the board.

The split matters more than the scores. Sealants bond to brick masonry where the chimney meets the roof; boots clamp round metal pipes. For a brick chimney, the sealants are the direct fix, and the boots only apply if a metal pipe also penetrates the roof.

Coverage is the other split. The ChimneySaver’s gallon and the MasonryDefender’s 14 sq ft per container are the only stated coverage figures; the boots are sized by pipe diameter instead, from 5 inches (Aothotop) to 18 inches (VEVOR). Measure the joint or the pipe before choosing, because an 18-inch boot will not help a 6-inch pipe and a gallon of sealant will not stretch across a whole roofline.

Best flashing for brick chimney: buying guide

Sealant vs boot

A brick chimney is masonry, usually rectangular: there is no round pipe for a boot to clamp. Brush-on sealants (ChimneySaver, MasonryDefender) are made for exactly this joint, bonding to brick, metal flashing and shingles. Save the boots (Sobalai, VEVOR, Aothotop) for round metal chimney and stove pipes.

Temperature range

Boots state theirs: +500F to -100F (Sobalai, Aothotop) or -101F to 437F (VEVOR). The sealants state none, which is normal for brush-on masonry products but worth knowing before they sit near a hot flue.

Warranty

ChimneySaver states 7 years with its fabric (sold separately); Sobalai states 2 years. The other three state no term. A warranty on a roof product is only as good as the install behind it.

Install

Sealants brush on about 1/8 in thick (ChimneySaver) with soap-and-water cleanup; boots trim to the pipe diameter and screw down, with sealant under the base (VEVOR). The Sobalai includes 50 screws and 2 hex bits; the others include screws or nothing stated. Whatever you use, the joint must be dry and clean first: sealant over wet moss or loose grit is a short-lived repair.

When to call a pro

Flashing is a roof job. If the chimney needs repointing, the roof is steep, or the leak has rotted decking, that is roofer work, not a sealant job. These picks suit sound flashing with cracked or failed sealant.

How much sealant

Work from stated coverage: 14 sq ft per container (MasonryDefender) or a full gallon (ChimneySaver) for a whole chimney base. The joint is the perimeter of the chimney where it meets the roof, plus any step flashing laps. Buy for the full perimeter at about 1/8 in thick; running short halfway around the chimney is how thin spots happen.

Boot sizing

Boots are sized by pipe outside diameter: 5-9 in (Aothotop), 7-13 in (Sobalai), 10-18 in (VEVOR). Measure the pipe, then trim the boot at the marked line for that size; cutting too high leaves a loose collar, and the listings warn to confirm size before cutting. The square base must sit flat on the roof, so very steep or uneven roofs need extra attention.

Color and looks

ChimneySaver comes in brown, black and tintable white; MasonryDefender is black only; boots here are red (Sobalai, VEVOR) or black (Aothotop). On a visible roof slope the color shows, so match the roof where you can and save the red boots for the back slope.

Around the Woodpile

• Roof work first: a sound ladder, dry conditions and fall protection before any sealant or boot goes on.
• Brush sealant about 1/8 in thick onto clean, dry masonry, per the ChimneySaver listing.
• Trim boots to the marked line for your pipe OD, and confirm the size before cutting.
• Do not exceed the stated temperature range on any boot.

Frequently Asked Questions

Can I use a pipe boot on a brick chimney?

No. Boots clamp round pipes; a brick chimney is rectangular masonry with no round pipe to clamp. Use a brush-on sealant for the brick-to-roof joint, and keep the boots for metal chimney and stove pipes.

Sealant or new flashing?

Sealant renews the waterproof bond on sound flashing: cracked sealant, small gaps, tired laps. If the metal flashing itself is rusted through, the mortar is failing or decking is soft, that is mason and roofer work, not a sealant job, and no brush-on product fixes it.

How thick should the sealant go on?

The ChimneySaver listing says about 1/8 in, filling all cracks and holes, with soap-and-water cleanup. Thin coats will not bridge gaps, so work from the stated coverage and buy enough for the full chimney perimeter.

Do I need the fabric with the ChimneySaver?

For the 7-year warranty, yes: it applies when used with FlashSeal Fabric, sold separately. Without the fabric, the warranty terms do not apply as stated, so factor the fabric into the real cost of the job.

What temperature can the boots handle?

Sobalai and Aothotop state +500F to -100F; VEVOR states -101F to 437F. Do not use any of them consistently beyond its stated range, and keep sealants away from direct flue heat since neither sealant states a temperature range.

How long does flashing sealant last?

The listings promise flexibility rather than a lifespan: both sealants stay flexible instead of cracking. The only stated duration is the ChimneySaver’s 7-year warranty with fabric. Plan on inspecting the joint each fall before burn season.

Related guides

See the stove accessories hub and our chimney sweep kit for a brick chimney picks. Compare stove pipe vs chimney pipe and chimney cleaning logs vs sweep kits.