Technical Jargon: Chimney Components

Advisory Report - October 2003

Technical Jargon: Chimney Components

“Technical Jargon” is a forum used to provide more information on terms commonly seen in U.S. Inspect reports.

To a lot of people, talking about the different components of a chimney is like speaking a foreign language.  The following diagram shows the components of a typical wood burning chimney.

Chimney Caps and Chimney Crowns

Keep in mind that the cap in the above diagram is different than a chimney crown--also called a wash or a splay.  A cap is generally pre-formed and overhangs the edge of the top of the chimney, as opposed to a crown, which is poured directly on top of the chimney. The chimney pictured on the right has a crown.

The chimney cap or crown should not to be confused with a rain cap or a chimney shroud or hood. 

A rain cap sits on top of the flue. 

A shroud or hood will project further above the flue termination and cover the top of the chimney.

Chimney Flashing

There is one last very important item to a chimney: flashing. Flashing is the building component used to connect and cover portions of a deck, roof, or siding material to another surface such as a wall, a chimney, a vent pipe or anywhere that runoff is heavy or where two dissimilar materials meet. The flashing is mainly intended to prevent water entry and is usually made of rubber, tar, asphalt or various metals. 

Click here to for more information more about Chimneys.

Contributed by Justin Gore
Quality Assurance Supervisor
U.S. Inspect, LLC

Diagrams used under license from The Illustrated Home, © 1998 Carson Dunlop & Associated Ltd.