The most common bad chimney flashing repair we see in Eau Claire is a coat of black roofing tar or a bead of caulk spread along the top edge of the counter flashing. Close behind it is a strip of metal screwed flat to the face of the brick with sealant along the top. Both of these stop the drip for a season or two. Then freeze-thaw cracks the sealant, water gets behind the metal, and the ceiling next to the chimney stains again. A brick chimney often outlasts several roofs, and every reroof and patch around it is another chance for someone to take that shortcut.
A proper repair takes more work, and the shortcut costs more in the end. Counter flashing belongs in a slot cut into a mortar joint. The step flashing underneath it has to be woven into the shingles one course at a time. When that’s how it’s built, the chimney rarely leaks at the roofline.
How chimney flashing works: step, counter, apron, and cricket
A chimney and the roof around it move independently, because the masonry sits on its own foundation and the roof framing swells and shrinks with the seasons. So chimney flashing comes in two layers that overlap without being fastened to each other.
| Piece | Where it goes | What it does |
|---|---|---|
| Step flashing | Sides of the chimney, one L-shaped piece per shingle course | Each piece laps the one below, so water running down the side gets turned back onto the shingles. It’s nailed to the roof deck, never to the brick |
| Counter flashing | Over the step flashing, tucked into a mortar joint | Covers the top edge of the step flashing so water running down the brick can’t get behind it |
| Apron (base) flashing | Downhill face of the chimney | One piece across the front, lying over the shingles below |
| Back pan or cricket flashing | Uphill face of the chimney | Catches water and snow coming down the roof and sends it around the chimney |
The uphill side causes the most trouble in Eau Claire. Without a cricket, snow piles up against the back of the chimney. Meltwater then sits against the back pan for days, freezing at night and thawing again in the afternoon. A cricket is a small peaked framed section that splits the flow and sends the water around both sides of the chimney.
Roof leaking around the chimney: flashing or masonry?
Before quoting any chimney flashing repair, we find out whether the water is getting in at the flashing or through the chimney itself. A brick chimney can soak up water above the roof and carry it down inside, past perfectly good flashing. Reflashing a chimney that leaks through its masonry gets you a bill and the same leak.
| What you see | Likely source | Who fixes it |
|---|---|---|
| Stain on the ceiling or wall beside the chimney during long, soaking rains | Step or counter flashing | A roofer |
| Wet roof boards on the uphill side of the chimney in the attic, worst during thaws | Back pan, or no cricket | A roofer |
| Tar, caulk, or screwed-on metal on the brick at the roofline | An earlier bad repair, usually over failed flashing | A roofer |
| Water in the firebox, the flue, or the cleanout | Missing cap or cracked crown | A chimney sweep or mason |
| Brick faces flaking off, or white mineral deposits on the brick in the attic | Porous or spalled brick soaking up water | A mason |
| Crumbling or missing mortar between bricks well above the roof | Failed mortar joints above the roofline | A mason |
| Brick inside the attic wet above the flashing line | Water coming through the masonry | A mason |
We repair chimney flashing as part of roof repair. We don’t rebuild chimneys, fix crowns or caps, reline flues, or repoint brick beyond the one mortar joint the counter flashing sits in. If the leak turns out to be in the masonry, we’ll tell you plainly and send you to a mason or chimney sweep, even though that means we don’t get the job. When the masonry and the flashing have both failed, the mason goes first. New counter flashing can’t be set into mortar that’s already falling out.
Water that has gotten into the masonry or behind old flashing freezes and expands every Eau Claire winter, so these problems get worse on their own. Tracing a chimney leak follows the same method as any other leak: find the trail in the attic first, then run a water test starting low and working up. The roof leak repair guide explains that process. A roof inspection is free and will usually settle the flashing-or-masonry question.
How chimney flashing repair gets done right
Counter flashing cut into the mortar joint vs. face-mounted and caulked
A proper counter flashing job on brick starts by cutting a slot, called a reglet, into a horizontal mortar joint with a masonry saw. The bent lip of the new counter flashing goes into that slot. Then the joint is re-pointed with mortar or sealed with polyurethane. On the sides of the chimney, the counter flashing is stepped to follow the roof slope, with each section set into its own joint. Water running down the brick passes over the top of the metal instead of getting behind it. HomeGuide says the same thing: installing new chimney flashing properly means cutting into the masonry.
Face-mounted (surface-mounted) counter flashing skips the cut. The metal is screwed or nailed flat to the brick, and a bead of caulk along the top edge is the only thing keeping water out. Rain running down the face of the chimney hits that bead constantly, and freeze-thaw opens it up. On the soft brick of older Eau Claire chimneys, sealant stuck to the brick face can pull the face right off when it lets go. We don’t face-mount counter flashing on brick. Metal or prefab chimneys boxed in with siding get flashed differently, more like a sidewall, and that’s one reason HomeGuide says they usually cost less to reflash.
Reseal or reflash?
Resealing makes sense when the flashing is already set in the mortar joint and the metal is sound, and only the sealant or mortar at the slot has failed. In that case we clean out the old material and reseal it with polyurethane or the manufacturer’s own sealant. Smearing roofing cement over the problem doesn’t count as resealing.
Reflashing is the right call when:
- the step flashing is rusted through, punched with nails, or was never woven into the shingle courses
- the counter flashing is face-mounted, buried under tar, or missing
- the chimney is wide enough to need a cricket and doesn’t have one
- the roof itself is near the end of its life
On that last point: asphalt roofs around Eau Claire usually last 18 to 25 years. If yours is close, reflashing the chimney now and then tearing the shingles off in a few years means paying for the flashing twice. In that case, do the chimney flashing as part of a roof replacement. And if the plan is to lay new shingles over the old ones, keep in mind that a roof-over usually leaves the old flashing in place. The roof-over vs. tear-off guide covers that trade-off.
Wisconsin code for chimney flashing: the 6-inch and cricket rules
Wisconsin’s dwelling code, SPS 321.28(7), sets out these chimney flashing requirements:
- Flashing is required wherever a chimney meets the roof.
- Chimneys have to be flashed and counter-flashed to a height of at least 6 inches.
- A cricket or saddle is required where the uphill side of a chimney is more than 30 inches wide on a sloping roof.
- The joint where the cricket meets the chimney has to be flashed and counter-flashed at least 6 inches up.
Many older Eau Claire houses have masonry chimneys wide enough to need a cricket: pre-WWII frame homes in the Third Ward and Randall Park, 1920s bungalows, and story-and-a-half houses. Often they never got one, and the back of the chimney has been collecting snow ever since. We measure the chimney before quoting. If it’s over the line, the cricket is in the quote.
As for permits: the City of Eau Claire exempts re-roofing under 200 square feet, Altoona exempts minor repairs valued under $5,000, and Chippewa Falls waives the permit under $2,000 of project value. A chimney flashing job normally falls well under all of those.
Chimney flashing materials: aluminum, galvanized steel, or copper
We bend step and counter flashing from aluminum or galvanized steel. Where the house already has copper, we use copper. Here are HomeGuide’s national figures:
| Material | Cost per linear foot | Lifespan |
|---|---|---|
| Aluminum | $5 to $10 | 15 to 20 years |
| Galvanized steel | $6 to $10 | Not listed |
| Copper | $15 to $30 | 50 to 100 years |
Material is the smaller part of the bill. HomeGuide puts labor at 60% to 70% of a chimney flashing job, because most of the work is cutting the joint, weaving the step flashing in, and re-pointing. The chimney’s surface matters too: HomeGuide says natural stone is harder to work than manufactured veneer, with brick in between.
Chimney flashing repair cost in Eau Claire
Our price for step or counter flashing at a chimney runs $400 to $1,800. The biggest factor in where a job lands is whether the mortar joint has to be cut and re-pointed. Reusing a sound slot costs less than sawing a new one into old brick. Chimney size, the type of masonry, and how many shingles have to come up also affect the price.
HomeGuide’s national figures land in about the same range:
| Job | National cost (HomeGuide) |
|---|---|
| Chimney flashing repair, average | $300 to $1,800 |
| Minor damage (small cracks, lifted edges), sealant or patching | $200 to $500 |
| Small chimney | $300 to $1,200 |
| Mid-sized chimney | $400 to $1,500 |
| Large chimney | $500 to $1,800 |
A chimney that has leaked for years usually costs more, because the water reaches the wood. If we open up the area and find soft roof boards around the chimney, the job moves into our larger repair range: $1,500 to $5,000 for bigger flashing or multi-spot repairs, and $2,000 to $6,500 and up when framing or decking is involved. The decking replacement guide explains what that work involves. Every quote is written, comes with photos of what we found, and follows a free estimate visit.
If water is coming in around the chimney right now, start with emergency roof repair. If wind tore the flashing loose or hail dented it, the storm damage page explains how insurance claims work. For anything else, call (715) 245-5271.