About

About Damper Guide

Damper Guide is a free tool for engineers, architects, contractors and inspectors who need to know whether a duct or air transfer opening needs a fire damper, smoke damper, combination fire/smoke damper, corridor damper or ceiling radiation damper.

What it covers

• International Building Code Section 717 (Ducts and Air Transfer Openings) in the 2018, 2021 and 2024 editions, with the sections it references for fire walls, fire barriers, shafts, fire partitions, corridors, smoke barriers, smoke partitions, exterior walls, floors and roofs.
• 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 penetration limits from Chapter 10.

How the rules are checked

Each rule was written from the code text of the edition it applies to, not from summaries or older guides. Each damper type is evaluated separately, so an exception that removes a fire damper does not hide a smoke damper that is still required. Every result shows the code sections it relies on so you can verify it.

• Sources: the 2024 IBC (August 2025 version) and 2024 IMC; the 2021 IBC (September 2021 printing) and 2021 IMC; the 2018 IBC (sixth printing) and 2018 IMC.
• Review: every rule change goes through several independent review passes that compare it with the code text, and a change is accepted only when the code text supports it.
• Testing: automated tests walk every possible answer path in all three editions before each update goes live.
• Corrections: problem reports from the result page are checked against the code text, and confirmed errors are fixed and tested.
• Last reviewed: October 12, 2026.

Limits

• The tool follows the model codes. Many states and cities amend these sections. Always check the amendments adopted where your project is.
• It does not decide what kind of wall or floor you have. Use the life safety plan or ask the design professional.
• Engineered smoke control systems, hazardous exhaust and special occupancies need project-specific review.
• The result is guidance, not an approval. The building official has the final say.

Read the code

The International Code Council publishes free read-only access to the codes:

• 2024 IBC Chapter 7
• 2021 IBC Chapter 7
• 2018 IBC Chapter 7

Privacy

There are no accounts and no advertising. The site uses Google Analytics, which sets cookies, to count visits (how Google uses this data). Your answers stay in your browser and in the page link; Analytics records only the code edition, the assembly and the type of result shown. If you send a problem report, it includes your message, your answers and, only if you enter it, your email address.

Found a problem?

Use "Report a problem with this result" at the bottom of any result. The report includes your answers, so the result can be checked exactly.

Damper Guide is an independent project. It is not affiliated with or endorsed by the International Code Council (ICC). International Building Code and International Mechanical Code are trademarks of the ICC. Code text is not reproduced here; requirements are summarized in plain language with section references.