: Contact page
- You can now send a question, a correction or a suggestion from the contact page. To report a wrong result, keep using the link at the bottom of the result, which attaches your answers.
About
Damper Guide updates
Changes to the rules, the code editions covered and the reference pages, newest first. The rules were last reviewed October 12, 2026.
: Guide pages for every assembly and damper type
- A guide to IBC Section 717 with a page for each wall, floor and ceiling assembly the tool covers. Each page lists every result the tool can give there, common situations side by side for the 2024, 2021 and 2018 editions, and the exceptions the tool checks.
- Pages for the 1-hour fire barrier exception, the shaft damper exceptions, and dryer, grease and hazardous exhaust ducts.
- A page for each damper type, and summaries of what changed in the 2021 and 2024 editions.
- The tool’s result now links to the guide page for the assembly and the damper types in the result.
IBC 717 guide · 2021 IBC damper changes · 2024 IBC damper changes
: Edition comparison and reviewed drawings
- A side-by-side comparison of damper requirements in the 2018, 2021 and 2024 IBC, with the section number each rule has in each edition.
- Illustrations can be enlarged, and the drawings were checked against the code text and corrected.
: Hazardous exhaust note corrected
- The note on Group H-5 semiconductor fabrication exhaust was incomplete. It now also says that semiconductor (HPM) exhaust ducts still may not pass through fire walls, need a shaft through fire barriers and floors, and may not have fire dampers.
: First release
- The damper tool covers IBC Section 717 in the 2018, 2021 and 2024 editions: fire walls, fire barriers, shaft enclosures, fire partitions, rated corridors, smoke barriers, smoke partitions, exterior walls, rated and unrated floors, and rated roof/ceilings.
- International Mechanical Code rules that prohibit dampers in clothes dryer exhaust, commercial kitchen grease ducts, hazardous exhaust and common multistory kitchen exhaust.
- Exit stairway and exit passageway enclosure limits from Chapter 10.
- Each damper type is evaluated separately, and every result cites the code sections it relies on.
Found something that looks wrong? Use “Report a problem with this result” at the bottom of any result in the tool. See how the rules are checked.