Chimney Flashing Repair — Step and Counter Flashing Rebuilt
A stain on the ceiling next to the fireplace, wet brick in the attic, a ring of roof cement around the chimney — the flashing rebuilt in metal, cut into the brick, so it stays fixed.
JMB Builders does chimney flashing repair on asphalt shingle roofs across the Twin Cities metro by rebuilding it, not caulking it: new step flashing woven into the shingles on each side, a new apron at the front, a cricket behind wide chimneys, and counter flashing cut into the mortar joints and sealed. Priced per unit for each chimney, quoted from your photos within one business day, on its own or with a reroof.
- Priced per unit, per chimney
- Step, apron, cricket and counter flashing rebuilt
- Quote from photos in 1 business day
- Licensed MN contractor BC809005
A chimney is the biggest hole in the roof, and the flashing around it is a two-part system. Step flashing goes under each shingle course up the sides and the apron goes under the shingles at the front; that layer moves with the roof. Counter flashing is let into the mortar joints of the chimney and bent down over the step flashing; that layer moves with the chimney. The joint between the two is what lets the roof and the masonry move separately without opening a gap. When a roofer skips the counter flashing and runs a bead of caulk along the brick instead, the caulk splits in a couple of winters and the leak is back.
We rebuild the whole system. Old flashing and the roof cement come off, the shingles around the chimney are lifted, ice and water membrane goes up the chimney base and out onto the deck, and new step flashing is woven in course by course. A wide chimney on the uphill side gets a cricket, a small peaked saddle that splits the water and snow around it instead of letting it pile against the back. Then the counter flashing is cut into the mortar joints with a grinder, set with a reglet or lead wedges, and sealed at the joint only.
The brick itself is a different trade. If the mortar is crumbling, the crown is cracked or the top courses are loose, we tell you and refer the tuckpointing or rebuild to a mason; flashing on a chimney that is falling apart does not hold.
What you supply
- Photos of the chimney from the yard on each side and, if you can, from a ladder showing the flashing and the shingles around it
- A photo of the stain or wet spot inside, and one from the attic if the chimney is visible there
- Whether the chimney is in use (furnace, water heater, fireplace) or capped off
What JMB supplies
- Removal of the old flashing, roof cement and any caulked-over patches
- Ice and water membrane at the chimney base, turned up the masonry and out onto the deck
- New aluminum or steel step flashing woven into each shingle course and a front apron
- A framed and shingled cricket behind the chimney where its width calls for one
- Counter flashing cut into the mortar joints, wedged and sealed at the reglet
- Matching shingles where the old ones crack when lifted
- A referral to a mason for tuckpointing, crown repair or a rebuild when the masonry needs it
- Photos of the flashing before the shingles go back, in your job folder
How it is priced: per unit
Quoted in writing from your photos within one business day. What moves the number:
- Chimney size: a narrow flue takes a few pieces, a wide fireplace chimney takes many and needs a cricket
- Whether a cricket has to be framed and shingled behind the chimney
- Brick or block with mortar joints for a reglet vs. a sided chase, which is flashed under the siding instead
- Roof pitch and how high up the roof the chimney sits
- Sheathing or framing repair around the chimney where the leak has been running
- Whether the shingles around it are brittle and have to be replaced in a wider area
- Doing it during a reroof, when the shingles are already off, vs. as its own visit
Photos of all four sides of the chimney from a ladder are the most useful; they show whether the counter flashing was ever cut in or just caulked.
How long it takes
One chimney: most of a day. Add half a day for a cricket or sheathing repair. During a reroof it is folded into the roof schedule.
How your project works
- 1
Send photos, get a written quote
Send three photos of the space and a sentence about what you want. You get a clear, itemized quote within one business day. We only come out to measure first when the job needs a tape measure — no pressure, no games.
- 2
Pick materials, or bring your own
We help you choose profiles and materials that fit the house and the budget, or match your existing millwork exactly — or you buy the door or trim yourself and we install it. Everything is confirmed before the crew is scheduled.
- 3
Clean, precise installation
The crew shows up on time, protects floors and furniture, and installs with tight joints and consistent reveals. Photos of the finished work go in your job folder.
- 4
Walkthrough and invoice
We walk the finished work with you. If anything is not right, we fix it before we call the job done. Then one invoice, paid by check or direct deposit — no card fees, no payment links.
Situations and options
Full step and counter flashing rebuild
The standard job: everything at the chimney comes off, membrane and new step flashing go in, and counter flashing is cut into the mortar joints. Done on a sound roof or as part of a reroof.
Cricket behind a wide chimney
Chimneys wider than a narrow flue need a saddle on the uphill side so snow and water split around the chimney instead of ponding against the back. We frame it, sheet it, membrane it and shingle it into the roof.
Sided chimney chase
A framed chase wrapped in siding is flashed with step flashing under the siding and a kick-out at the bottom, not counter flashing in mortar. We pull the lower siding, flash it right and put the siding back; rotted chase sheathing is replaced first.
Reflash with a new roof
Every chimney gets new step and counter flashing during a reroof; that is the cheapest time to add a cricket or fix the sheathing around it. It is a listed line on our roof replacement quote.
Chimney Flashing Repair — Step and Counter Flashing Rebuilt: questions, answered
Why is water leaking around my chimney?
Nearly always the flashing. Counter flashing that was caulked to the brick instead of cut into the mortar splits open within a few winters. Step flashing that was face-nailed or skipped lets water under the shingles on the sides. Behind a wide chimney with no cricket, snow and water pile against the back and find the top. Less often it is the masonry itself: a cracked crown or open mortar joints letting water down through the brick, which is a mason's job.
Can chimney flashing be repaired without replacing the roof?
Yes. We lift the shingles around the chimney, rebuild the flashing and weave the shingles back. On a roof with shingles that still bend without cracking it leaves no trace. If the shingles are brittle, we replace the courses around the chimney with matching shingles and tell you what that says about the rest of the roof.
What is the difference between step flashing and counter flashing?
Step flashing is the L-shaped piece tucked under each shingle course along the side of the chimney; it belongs to the roof. Counter flashing is the piece let into the mortar joint above and bent down over the step flashing; it belongs to the chimney. The two overlap without being fastened to each other, so the roof and the masonry can move separately and the joint stays covered. A chimney with only one of the two will leak eventually.
Does my chimney need a cricket?
If the chimney is wide enough that snow and water pile up behind it instead of running around, yes. Narrow flue chimneys usually do not; wide fireplace chimneys on the uphill side of a roof almost always do. The code has a width threshold, and we build to it. A cricket is framed, sheeted, covered in membrane and shingled so it reads as part of the roof.
Do you repair the chimney brick and mortar too?
No, that is masonry. If we see crumbling mortar, a cracked crown, spalled brick or a loose top course, we tell you and refer you to a mason for tuckpointing or a rebuild, and we time the flashing so it is done after the masonry work, not before. Flashing cut into bad mortar does not hold.
Is roof cement around a chimney a proper repair?
No. A bead of roof cement or caulk along the brick is a patch that lasts a season or two, dries out and cracks, and hides what was wrong underneath. If your chimney has a thick black band around its base, that is where the water is getting in. We remove it and rebuild the flashing in metal so the repair does not have to be repeated.
Get a written quote for this job
Three photos and a sentence is enough. You hear back within one business day. Or text the photos to 763-204-2099.
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Read morePage reviewed September 24, 2026 · JMB Builders LLC, MN license BC809005 · All roofing pages
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