A chimney flashing kit is a pre-formed set of metal pieces (apron, step, and counter flashing) sold together to seal the joint where a chimney passes through the roof. Most kits run $40 to $210 depending on the metal and chimney size, fit a single-flue chimney up to about 32 by 32 inches, and remove most of the sheet-metal bending a custom job would need. This guide compares the kit types, shows what is inside each one, explains how to size a kit to your pitch and chimney material, and names when a pre-fab kit beats custom flashing.
What is a chimney flashing kit?
A chimney flashing kit is a packaged assembly of bent metal parts that waterproofs all four sides of a chimney where it meets the roof deck. Instead of a roofer folding each piece from flat coil stock on site, the kit ships the front apron, the side step pieces, and the counter flashing pre-cut and pre-bent. Standard kits are built for asphalt shingle roofs, with separate versions for metal panel roofs.
The buyer is usually a homeowner replacing a leaking chimney flashing, a DIYer doing a re-roof, or a roofer who wants to skip on-site fabrication. Brands you will see on the shelf include Gibraltar Building Products, Moheco (Uniflash), SuperFlash, Spectra, and Flashing Kings.
What is inside a chimney flashing kit?
A full chimney flashing kit contains four part types that work as a layered system: an apron at the low side, step pieces up each side, a back pan or cricket at the high side, and counter flashing that caps the whole assembly. Water sheds from the counter flashing onto the step and apron pieces, then back onto the shingles below the chimney.
| Part | Where it goes | What it does |
|---|---|---|
| Apron (head) flashing | Downhill face of the chimney | Diverts water running down the roof around the front of the chimney |
| Step flashing | Both sides, one piece per shingle course | Layers between shingles so each course drains over the one below |
| Back pan or cricket flashing | Uphill face | Splits water and debris around the high side to stop ponding |
| Counter flashing | Over the step and apron, into or against the chimney wall | Caps the base flashing so no open seam faces the weather |
A basic kit may bundle only the apron and step pieces, leaving the counter flashing to be cut in separately. A complete kit includes counter flashing too. Check the parts list before buying so you are not short a layer on install day.
Types of chimney flashing kits
Chimney flashing kits fall into four practical types, sorted by how the chimney sits on the roof and what it is built from. The right type depends on your chimney material (brick versus siding), roof pitch, and whether the uphill side needs a cricket to shed water.
| Kit type | Best for | Typical metal | Notes |
|---|---|---|---|
| Step-and-counter kit (for example Moheco Uniflash) | Standard brick chimney on a shingle roof | Aluminum or galvanized steel | Two-layer set, patented Uniflash design dates to 1992 |
| Saddle or cricket kit (for example Flashing Kings) | Wide chimneys that trap water and snow uphill | 26 gauge G-90 galvanized, soldered seams | Rated to a pitch range, often 3/12 to 6/12 |
| Surface-mount one-piece kit (for example Gibraltar, SuperFlash) | Fast DIY replacement without stripping shingles | 28 gauge galvanized steel | Around 18 pre-cut components, fits up to 32 by 32 inches |
| Metal-roof panel kit | Chimneys on standing-seam or corrugated panels | Metal matched to the panel | Sized to the panel rib profile, not to shingles |
Metal chimney flashing on a panel roof is a different problem from shingle flashing because the counter flashing has to clear the rib height and allow the panel to move with heat. For that case, read our guide to chimney flashing for a metal roof before you buy a shingle kit that will not seat.
Brick chimney flashing differs from siding or stucco in one detail: the counter flashing has to tuck into a cut mortar joint (a reglet), then get sealed. On a sided chimney the counter flashing slips up behind the siding instead. Buy a kit whose counter flashing matches your wall type.
How much does a chimney flashing kit cost in 2026?
A chimney flashing kit costs about $40 to $210 for the parts alone in 2026, driven mainly by the metal and the chimney size. A basic galvanized steel kit sits at the low end, while a soldered saddle kit or a copper kit sits at the top. Sheet-metal prices have climbed with wider building-material inflation, which our roofing material price and inflation index tracks against CPI.
| Kit or brand | Material | Fits up to | Parts price |
|---|---|---|---|
| Gibraltar galvanized steel kit | 28 gauge galvanized | 32 by 32 in | About $42 |
| SuperFlash or Moheco Uniflash | Aluminum or galvanized | Single flue | Often $60 to $150 |
| Flashing Kings 30 in saddle kit | 26 gauge G-90 galvanized | 30 in width, 3/12 to 6/12 pitch | About $208 |
| Copper kit | Copper | Single flue | Often $250 to $600 |
Parts are only half the number. Professional installation typically adds $200 to $500 in labor because the counter flashing usually means cutting a reglet and lifting shingle courses. A full chimney re-flash, parts and labor together, often lands between $300 and $1,000 depending on chimney size, chimney height, and roof access.
What metal should a chimney flashing kit be?
Chimney flashing kits come in four common metals, and the pick trades cost against lifespan and how well the metal takes a bend. Galvanized steel is the default and the cheapest. Copper and lead-coated copper cost the most but outlast the roof they sit on.
| Metal | Typical thickness | Rough lifespan | Relative cost | Best use |
|---|---|---|---|---|
| Galvanized steel | 26 to 28 gauge | 20 to 30 years | $ | Most shingle-roof kits |
| Aluminum | 0.019 to 0.032 in | 25 to 40 years | $ | Easy bending, will not rust, avoid direct contact with masonry lime |
| Copper | 16 oz | 50 to 100 years | $$$$ | Historic homes, copper or slate roofs |
| Lead or lead-coated copper | Varies | 50 years plus | $$$ | Molds tightly into brick reglets |
Match the flashing metal to the roof and to nearby metals. Bare aluminum against fresh masonry can corrode over time, and mixing copper with steel fasteners drives galvanic corrosion. When in doubt, keep the flashing, drip edge, and fasteners in the same metal family.
How to size a chimney flashing kit to your chimney and roof
Sizing a chimney flashing kit takes three measurements and two checks: chimney width, up-roof depth, roof pitch, plus the chimney material and whether the uphill side needs a cricket. Get these before you buy, because a kit that is too small leaves an open seam and a kit rated for the wrong pitch will not lie flat.
- Measure the chimney width across the downhill (low) face. Most one-piece kits fit up to 32 by 32 inches, and single-flue kits often cap at 24 by 24 inches.
- Measure the up-roof depth, the chimney dimension running uphill. A chimney wider than 30 inches on the uphill side usually needs a cricket or saddle to shed water.
- Read your roof pitch and check it against the kit rating. Many saddle kits are cut for 3/12 to 6/12; a steeper roof needs a kit made for that slope.
- Identify the chimney material. Brick and block need counter flashing that cuts into a mortar joint; siding and stucco take counter flashing that tucks behind the wall surface.
- Confirm the roof covering. A shingle kit will not seat on metal panels, and a metal-panel kit is sized to the rib, not the shingle course.
Chimney flashing repair kit versus a full kit
A chimney flashing repair kit replaces only the top layer, the counter flashing and its sealant, without stripping shingles. A full chimney flashing kit replaces the base layer too (the step and apron pieces that sit under the shingles), which means lifting shingle courses. The right choice depends on which layer failed.
- Use a repair kit when the step and apron flashing under the shingles is still sound and only the counter flashing pulled loose, cracked, or lost its sealant at the mortar line.
- Use a full kit when the step flashing is rusted through, was never installed, or the shingles around the chimney are coming off anyway during a re-roof.
- Reach for a full re-flash when leaks return after two sealant repairs, because caulk is a stopgap, not the fix.
If you are chasing a leak rather than planning a replacement, diagnose it first. Our guide to a chimney flashing leak and its six failure modes shows how to tell a counter-flashing problem from a step-flashing or cricket problem before you spend on parts.
Kit versus custom-fabricated flashing: which to choose
A pre-fab kit wins on a standard chimney at a standard pitch; custom fabrication wins on anything unusual. The retail listings that sell these kits rarely say where the line is, so here is the decision most product pages skip. Match your situation to the column below.
| Factor | Pre-fab kit | Custom fabricated |
|---|---|---|
| Chimney size | Within the kit range (up to about 32 by 32 in) | Oversized or multi-flue chimney |
| Roof pitch | Inside the kit rated slope | Very steep or very low slope |
| Metal match | Galvanized, aluminum, common copper | Matching an existing copper, slate, or historic roof |
| Cricket need | Kit includes a saddle for the width | Wide chimney needing a built cricket sized on site |
| Parts cost | $40 to $210 plus labor | Often $300 to $1,000 fabricated and installed |
For a wide chimney, the uphill cricket is where kits most often fall short. If your chimney is more than 30 inches across the up-roof side, price a built saddle: our chimney cricket install guide covers when code requires one and how it is sized. For the full install sequence of step and counter flashing, see the learn hub on roofing details.
Frequently asked questions
What is a chimney flashing kit?
A chimney flashing kit is a pre-cut, pre-bent set of metal pieces that seals the joint where a chimney meets the roof. A full kit includes apron flashing for the front, step flashing for the sides, back or cricket flashing uphill, and counter flashing that caps the assembly. Kits save a roofer from bending each piece from flat coil stock on the roof.
How much does a chimney flashing kit cost?
A chimney flashing kit costs about $40 to $210 for the parts in 2026. A basic 28 gauge galvanized steel kit runs near $42, while a soldered galvanized saddle kit runs about $208, and copper kits often reach $250 to $600. Professional installation typically adds $200 to $500, so a full re-flash often totals $300 to $1,000.
Can I install a chimney flashing kit myself?
A surface-mount one-piece kit is DIY-friendly on a low to moderate pitch, since it fastens over the shingles and existing base flashing. A full kit is harder because it means lifting shingle courses and, on a brick chimney, cutting a reglet into the mortar for the counter flashing. If the roof is steep or the leak source is unclear, hiring a roofer is often the safer call.
Do chimney flashing kits work on brick chimneys?
Yes, most kits are made for brick chimneys, but the counter flashing has to seat into a cut mortar joint called a reglet, then get sealed. On a sided or stucco chimney the counter flashing tucks behind the wall surface instead. Confirm the kit counter flashing matches your chimney material before you buy.
What are the four parts of chimney flashing?
The four parts are apron flashing on the downhill face, step flashing up both sides, back pan or cricket flashing on the uphill face, and counter flashing that caps the base pieces. The base pieces sit under the shingles and against the chimney; the counter flashing overlaps them and ties into the chimney wall so no open seam faces the weather.
When should I use a chimney flashing repair kit instead of a full kit?
Use a repair kit when only the counter flashing or its sealant failed and the step and apron flashing under the shingles is still sound. Use a full kit when the step flashing is rusted, was never installed, or the shingles are coming off during a re-roof. If leaks return after two sealant repairs, replace the full assembly rather than recaulk again.
Reviewed by The Roofing Brief Team. Last reviewed July 2026.