Rusted-Through Chase Cover Replaced With Custom Stainless Steel in Louisville, KY
Documented by David York, Owner
A Louisville homeowner's chimney was streaking orange rust stains down the brick. The cause was on top of the chimney: the original galvanized chase cover had rusted through and was letting water pool and drip into the chase. We fabricated and installed a custom-fit stainless steel chase cover with a sloped, water-shedding design, reinstalled the existing cap, and finished by applying a breathable water repellent to the surrounding masonry.
Before
Before
After
AfterProblem Identified
A chase cover is the metal lid on top of a framed chimney chase, and the builder-grade default is galvanized steel. It looks fine for a few years, then the finish fails and it rusts. Once that happens, water sits on the flat top instead of draining, works into the fastener holes and seams, and drips straight down into the chase where you can't see it until there is interior damage. The rust runoff also carries down the face of the brick as the ugly orange staining this homeowner noticed. A rusted-out chase cover is one of the most common hidden sources of a chimney leak.
What We Found
- A galvanized chase cover rusted through across the top, with water pooling instead of draining
- Orange rust runoff staining streaking down the exterior brick
- Fastener and collar penetrations where water was getting past the failing metal
- Masonry that had been absorbing moisture and would benefit from sealing to slow future saturation
Work Performed
- Measured the chase and fabricated a custom-fit chase cover from stainless steel, which will not rust out like galvanized
- Removed and disposed of the old rusted cover
- Built the new cover with a sloped, hipped profile so water sheds off instead of pooling on top
- Sealed the collar and fastener points with industrial-grade sealant and mechanically fastened the new cover to the chimney
- Reinstalled the existing chimney cap onto the new stainless cover
- Applied a professional-grade breathable water repellent to the exterior masonry
Outcome
The chimney sheds water the way it is supposed to again. The new stainless steel cover will not rust out the way the galvanized one did, the seams and collar are sealed against water intrusion, and the breathable repellent slows moisture from soaking into the brick without trapping it inside. The orange staining stops here. A custom stainless steel chase cover with masonry waterproofing like this typically runs in the $1,500 to $2,500 range, depending on the size of the chase and roof access. Replacing a failed chase cover is one of the most cost-effective repairs on a chimney — far less than fixing the interior water damage a rusted-out cover eventually causes.
Seeing something similar on your chimney? See a related chimney cap and chase cover project in Mockingbird Valley, or browse all of our documented projects.
Orange Stains on Your Brick? Your Chase Cover May Be Rusting Out
Rust streaks running down a chimney almost always trace back to a failing chase cover — and a chase cover that is leaking water into the chase can cause damage you never see from the ground. We will get on the roof, show you exactly what is happening with photos, and give you an honest answer about what it needs.