Cedar Hills · Utah County
Chase Covers and Caps on Cedar Hills Chimneys
Almost nobody has looked at the top of their own chimney. On a framed chase, that flat sheet of metal up there is the only thing between weather and the timber inside.
Cover, cap, crown: three different things
The words get used interchangeably and they should not be. A crown is the sloped concrete top of a masonry chimney. A chase cover is the sheet metal lid on a framed chase. A cap is the small hood over the flue opening itself, with mesh in the sides. Cedar Hills chimneys mostly have a cover and a cap, and no crown at all.
That matters because a contractor quoting crown repair on a house that has no crown either has not looked, or is describing something else.
Why the standard cover fails
The covers fitted through the main building era here are typically galvanized steel, cut flat, with a hole for the flue pipe. Three things go wrong with that, and they go wrong in sequence.
Flat means water stands on it rather than running off. Standing water on galvanized steel takes the coating off, and once bare steel is exposed it rusts, first as staining down the veneer and then as a perforation you cannot see from the ground. And because the cover was cut flat with no drip edge, the water that does run off travels back underneath the lip and onto the top of the chase wall by surface tension.
The storm collar around the pipe is on a similar clock. It relies on sealant, sealant hardens and cracks, and when it opens, water runs down the outside of the flue pipe straight into the chase interior. That one drips onto framing directly.
What a proper replacement looks like
Stainless steel, sized to overhang the chase on all sides, with a cross-break so the middle is high and water sheds to the edges, a hemmed drip edge so it leaves the metal instead of tracking back, and a new collar properly sealed at the pipe. Fitted that way it is a component you stop thinking about, rather than one you re-seal every few years.
The cap on the flue
On a listed metal chimney, the rain cap is part of the certified system and should be the manufacturer's component for that pipe, not a universal cap that happens to fit. It keeps rain out of the flue, keeps birds and rodents out of a warm vertical shaft, and its mesh arrests sparks. Missing or damaged caps are worth replacing quickly, because everything that gets into an open flue then has to be removed from the appliance below.
Questions
Caps & Dampers in Cedar Hills — common questions
How do I know if my chase cover needs replacing?
The clearest sign from the ground is rust staining running down the chimney face, which means water has been standing on the cover long enough to eat through the galvanizing. Any visible sag or ponding is another. Both mean water is likely reaching the framed structure underneath, which is a far more expensive problem than the cover.
Can a chase cover just be sealed instead of replaced?
Sealant buys time on a cover that is still structurally sound, and there are situations where that is the right call. It is not a repair for one that is already perforated or holding water in the middle, because the underlying shape is what caused the failure. Replacing it in stainless with a cross-break solves it once.
What is the collar around the pipe and why does it leak?
The storm collar is a metal band sealing the gap where the flue pipe passes through the cover. It depends on a bead of sealant, and sealant hardens and cracks with sun and temperature cycling. When it opens, water runs down the outside of the pipe into the chase, which is one of the more damaging leaks because it lands directly on framing.
Does the rain cap have to be the same brand as the chimney?
On a listed metal chimney system, yes, it should be the component the manufacturer specifies for that pipe. The system is certified as an assembly, and a generic cap that fits physically is not the same as one that is part of the listing. It is also usually a better fit for the pipe's actual diameter and draft requirements.
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