What is a Storm Collar? | TSE Glossary
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What is a Storm Collar?
A storm collar is a sheet-metal collar that wraps around a chimney pipe at the joint between the pipe and a flashing or chase cover, sealing the gap to keep water from running down the pipe into the structure below. The collar is typically a split-ring design that clamps around the pipe and is sealed to it with high-temperature silicone caulk. It is the second line of defense after the flashing or chase cover itself.
How it works
The storm collar slides over the chimney pipe and rests against the upturned flange of the flashing or chase cover, with the collar’s slight downward bell directing water away from the pipe-cover joint. High-temperature silicone caulk applied between collar and pipe creates a watertight seal that allows for thermal expansion. The split-ring configuration accommodates removal and reinstallation during chimney service.
Storm collars require periodic re-caulking because the silicone deteriorates from UV exposure and thermal cycling. A failing storm collar produces interior staining around the chimney chase or attic framing where the pipe penetrates. Sweeps inspect storm collar condition during CSIA Level 1 visits and re-caulk or replace as needed. Original galvanized storm collars usually outlast original chase covers, but replacement is cheap insurance during major service.
DFW context
DFW storm collars on prefab chimneys often need re-caulking every 5 to 7 years due to Texas UV exposure and the temperature swing between winter chimney use and 100-plus degree summer roof surfaces. TSE replaces or re-caulks storm collars during every chase cover service and during any work that disturbs the existing seal. Stainless storm collars paired with high-quality silicone deliver durable service in DFW conditions.
Related terms
- [Chase cover](/glossary/chase-cover/)
- [Crown](/glossary/crown/)
- [Flue tile](/glossary/flue-tile/)
- [Class A chimney](/glossary/class-a-chimney/)
Sources
- NFPA 211 (2024), Section 9.7
- IRC 2021, Section R1005
- UL 103 HT chimney standard
Our Sister Companies — Specialists in Related Services
Texas Service Experts is part of a network of CSIA-certified chimney specialists. Depending on your specific need:
- Texas Chimney Experts — chimney repair/masonry
- Prime Chimney Experts — multi-state national service