Rusted chimney chase covers replaced in Egypt Lake-Leto

The small gap left around the chimney pipe

The collar is meant to sit close to the chimney pipe without being fastened or sealed to it. The same installers manual calls for a gap of one eighth of an inch around the flue pipe and carries a fire-risk warning against caulking the pipe to the chase top collar.

That warning surprises homeowners who have seen tar or silicone packed around the pipe. We remove that kind of improvised sealing, leave the gap the instructions describe and rely on the storm collar above it to keep rain out. Following the instructions is safer than improvising at the top of a chimney.

Sealing the storm collar the right way

A storm collar is the metal band that wraps the chimney pipe just above the collar on the cover. It sheds rain away from the gap around the pipe. The installation instructions for one common system call for caulking the gaps between the storm collar and the pipe, and between the storm collar and the chase top collar.

The same instructions warn against blocking the air holes at the termination. We seat the storm collar snugly, seal only where the instructions say to and leave every vent opening clear. A storm collar that has slipped or lost its seal is a simple source of leaks and one of the first things we check.

When a chase cover can be repaired instead

Not every leaking chase cover needs replacing. A cover in sound metal with one open seam, a loose fastener or a storm collar that has slipped can often be repaired, and the estimate shows that smaller repair when it fits.

Replacement makes sense when the metal is rusted through in several places, when the cover holds water across its surface or when it was never shaped to drain. Patching those covers tends to buy a short time before the next leak.

• Repair: one failed seam, loose fasteners or a slipped storm collar on sound metal
• Replace: rust holes, a dished surface or an opening with no raised collar
• Look further: soft framing, wet insulation or stains well below the top

What our free chase inspection includes

The free inspection covers the parts that keep water out at the top of the chase. That means the cover, its seams and fasteners, the collar, the storm collar, the cap and the edge where the cover meets the siding. We also look at the fireplace below for signs of water.

You get a plain explanation of what is sound and what is failing, and a written price for the work we recommend. The inspection costs nothing and commits you to nothing, and if you approve the work within 72 hours of it, you save 10%.