This job started the way a lot of Arvada cap jobs do: a homeowner noticed the top of the chimney looked bare from the yard, and a downdraft smell had crept into the house on windy days. The cap that once sat on the metal flue had rusted through and blown off, leaving the pipe open to the sky. We measured the flue, brought up a stainless spark-arrestor cap to match, and closed the whole thing up in a single rooftop visit.
| Where | Arvada, Colorado |
|---|---|
| The trade | Chimney cap installation |
| What we found | A rusted, missing cap on an open metal flue |
| What we fitted | A stainless spark-arrestor cap, sized to the flue |
| Also done | Flue collar sealed, chase cover seams finished |
| Time on site | A single rooftop visit |
An open flue is an invitation
A chimney with no cap is open to three things at once, and none of them are good. Rain and snowmelt pour straight down onto the damper and into the firebox, rusting steel and working moisture into masonry. Birds and squirrels treat the warm pipe as a ready-made nest. And on a wood-burning flue, embers can ride the draft right up and out onto the roof. The cap that failed here had been doing all of that work quietly until it gave up, so the first job was simply to close the flue back off.
Measured at the flue, not guessed from the truck
A cap only works if it fits the flue it sits on. Our tradesman measured the galvanized pipe on the roof and matched a stainless spark-arrestor cap to it, rather than forcing on whatever happened to be on the truck. The mesh sides are the spark arrestor and the animal screen in one, and a stainless body is what survives the hail, snow load and chinook wind that Arvada rooftops take every year.
A cap is the cheapest thing on the roof and it guards the most. We would rather fit one in the summer sun than chase the water damage it would have let in.
- The Olde Town Chimney crew
The seal is the part you pay for
Setting the cap is the quick part. The seal is the job. With the cap seated square, the collar where it meets the flue gets a full weatherproof bead worked all the way around, so wind-driven rain has no path to sneak in behind it. While the crew was up top, the metal chase cover got its seams sealed too, so the entire top of the chase sheds water instead of pooling it.
Closed up before winter asks anything
By the time the crew climbed down, the flue was closed to weather and wildlife and open to a clean draft, exactly the way it should be. The downdraft smell goes with the gap that caused it, and the firebox and damper underneath stop taking on water. It is a small repair that protects a lot of chimney, which is why we would rather a homeowner call about a bare-looking cap in July than a rusted damper in January.
Anybody can set a cap on a pipe. Sealing the collar so it stays watertight through a Front Range winter is the part that makes it a repair instead of a photo.
- The Olde Town Chimney crew
If the top of your chimney looks bare from the yard, or you catch a draft smell on windy days, that is usually a cap doing a poor job or no cap at all. Ring the Olde Town Chimney workshop and we will get a tradesman up for a look, here in Arvada, with the quote in writing before any work starts.
