Thornton Roofing Pros provides professional chimney flashing in Thornton, CO for residential and commercial properties across the north Denver metro. Chimney flashing is the detail production builders cut most consistently, and it produces the leak we are called about most often. The tract method was a surface-mounted counterflashing lapped onto the brick and sealed with caulk, and caulk was never a permanent detail — it was a fast one.
The correct assembly has three parts and they are separate. Step flashing woven into each shingle course as it goes up the side. A counterflashing set into a saw-cut reglet in the mortar joint, folded down over the steps and mechanically secured. And an apron at the front and a saddle at the back. If one is missing, the other two will not save it, and a repair that only replaces caulk has a two-year life.
The back of the chimney is where the water actually gets in. A wide chimney on a shingled slope with no cricket behind it forms a shelf that holds snow and debris against the masonry all winter. Sizing and framing a cricket — a small hip roof shedding water around either side — is real work and it is the permanent fix. We will tell you when a chimney is narrow enough not to need one.
Framed chases are a different animal, and there are many in the 1990s and 2000s filings: a wood-framed box with siding and a sheet-metal chase cover on top. Those covers were often galvanised, flat, unpainted and undersized, so they rust through and water runs down inside the chase, unseen until a ceiling stains. Replacement is a custom-fabricated stainless or Kynar-finished cover with a cross break for drainage and a proper drip edge.
Kickout flashing is the omission with the largest consequences. Where a roof meets a wall and stops, without a kickout diverting water out onto the shingles, the flow runs behind the siding into the wall cavity. It shows up as interior damage far from the roof and is regularly misdiagnosed as a window leak. Adding one is inexpensive; finding it years later is not.
We do not seal our way out of chimney leaks. If the counterflashing is surface-mounted we cut a reglet. If there is no cricket and the chimney needs one, we quote framing it. And we will say plainly when the masonry itself is the leak — spalled brick or an open crown is a mason's job, and flashing it better will not stop water coming through the chimney from above.
Our licensed and insured team brings the right materials and equipment to every job — 7/16-inch OSB and 1x6 plank roof decking, synthetic underlayment fastened with plastic cap nails, six-nail high-wind fastening patterns, UL 2218 Class 4 impact-rated laminate shingles, 24-gauge standing seam steel with concealed clips, SBS polymer-modified bitumen base and cap sheet — and backs the work with a written workmanship warranty. We serve Thornton and nearby communities including Northglenn, Federal Heights, Commerce City, Brighton.
What We Handle
Everything our chimney flashing in Thornton covers
One crew, one point of contact, and the full range of chimney flashing work in Thornton, CO. If it is on this list we do it in house rather than handing it to a subcontractor:
- chimney flashing repair Thornton
- chimney leak repair Thornton CO
- step flashing replacement
- counterflashing reglet cut
- chimney cricket installation
- chimney chase flashing
- chase cover replacement
- chimney saddle install
- kickout flashing installation
- chimney flashing cost
- masonry chimney leak
Not sure which one describes your situation? Describe it in plain words and we will sort it out — or browse the rest of our Thornton services.
Materials, equipment and how we do chimney flashing
The difference between chimney flashing that lasts and chimney flashing that gets redone in three years is almost always preparation and materials, not the finish you see on day one. We work with 7/16-inch OSB and 1x6 plank roof decking, synthetic underlayment fastened with plastic cap nails, six-nail high-wind fastening patterns, UL 2218 Class 4 impact-rated laminate shingles, spec them to the job instead of to the invoice, and write the material grades into the free estimate so you know exactly what you are buying.
Every Thornton job runs the same way: site walk and measurements, written scope and fixed price, protection of the surrounding area, then the work itself with a daily clean-up. Years of roofing work in the north Denver metro means we have already met whatever your property is going to throw at us — awkward access, older construction, an HOA with opinions.
Where we do chimney flashing outside Thornton
Thornton Roofing Pros covers Thornton and the surrounding communities of the north Denver metro. Crews run out to the same nearby cities every week, so an out-of-town job does not mean an out-of-town price.
- Chimney Flashing in Northglenn, CO — Adams County, population 38,131
- Chimney Flashing in Federal Heights, CO — Adams County, population 14,382
- Chimney Flashing in Commerce City, CO — Adams County, population 62,418
- Chimney Flashing in Brighton, CO — Adams County, population 40,083
- Chimney Flashing in Westminster, CO — Adams County, population 116,317
- Chimney Flashing in Broomfield, CO — Broomfield County, population 74,112
Start on the Thornton Roofing Pros homepage for a free estimate, or call (844) 511-2320 and describe the job.
Why Thornton Chooses Thornton Roofing Pros
- ✓We date your roof by cohort before quoting it — layer count at the rake, shingle profile, fastening pattern and decking type — because that tells us what the job actually is.
- ✓Every estimate shows two columns: the builder specification replaced like for like, and what each upgrade costs on top, so you can see the price of a ridge vent or drip edge on its own.
- ✓Penetrations are counted and priced individually. Furnace flues, radon stacks, bath fans, swamp-cooler curbs and skylights are separate flashing details, not a lump-sum allowance.
- ✓We inspect the attic with a moisture meter and check soffit intake on every job, because ventilation defects shorten shingle life and they are invisible from the driveway.
The standards behind chimney flashing
Quality here is not a matter of opinion — it is written down. The chimney flashing work we do in Thornton follows published industry standards: NRCA publishes the Roofing Manual, the industry's reference for details and slope minimums, and Asphalt Roofing Manufacturers Association sets the shingle application and ventilation guidance the warranties reference. If a contractor cannot tell you which standard a detail comes from, that is worth asking about before you sign.
Every chimney flashing project in Thornton gets the same attention, whether it is a single room or a full commercial job. We show up on schedule, keep the site clean, and stand behind the work — the estimate is free and there is no pressure.
Ready to get started? Call (844) 511-2320 for a free chimney flashing free estimate in Thornton, or request a quote and we'll get right back to you.