# Clarification on a roofing Question? **URL:** \ **Category:** Misc. Discussion\ **Created:** [June 30, 2026, 2:38pm UTC](https://forum.nachi.org/t/clarification-on-a-roofing-question/268750 "2026-06-30T14:38:28Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![ehochban](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/ehochban/32/250901_2.png) [@ehochban](https://forum.nachi.org/u/ehochban)\ **Post date:** [June 30, 2026, 2:38pm UTC](https://forum.nachi.org/t/clarification-on-a-roofing-question/268750/1 "2026-06-30T14:38:28Z")
![image](https://global.discourse-cdn.com/internachi/original/4X/c/8/b/c8b09f2ffbb5ed662c253c84541920aeaa33f59e.jpeg) In areas where there is a history of ice forming along the eaves, causing a backup of water, an ice barrier that consists of at least two layers of underlayment cemented together, or a self-adhering, polymer-modified bitumen sheet, shall be used in lieu of normal underlayment, and extend from the lowest edges of all roof surfaces to a point at _ **least 24 inches** _ inside the exterior wall line of the building. Detached structures without conditioned areas are the exception. I would, I would just like some clarification. In the diagram it shows 818 to 24 inches and then text description is shows at least 24 inches? ---
**Author:** ![jjonas](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jjonas/32/301755_2.png) [@jjonas](https://forum.nachi.org/u/jjonas)\ **Post date:** [June 30, 2026, 3:21pm UTC](https://forum.nachi.org/t/clarification-on-a-roofing-question/268750/2 "2026-06-30T15:21:06Z")
Based on my area in Minnesota, you are “more correct” than that outdated (11+ years old) and poorly drawn graphic. I have lived in multiple “snow/ice states”, and many of them required 36" inches beyond the Exterior Wall line, with 24" inches being the typical **minimum**! Thank God that (some) Staff has finally began to post new graphics on the MB for them to be vetted by actual inspectors! ![IS](https://global.discourse-cdn.com/internachi/original/4X/d/7/1/d71f390b8c7ff67f45db93618abf5989b83fc2a3.jpeg) ---
**Author:** ![sfetty](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/sfetty/32/331195_2.png) [@sfetty](https://forum.nachi.org/u/sfetty)\ **Post date:** [June 30, 2026, 3:33pm UTC](https://forum.nachi.org/t/clarification-on-a-roofing-question/268750/3 "2026-06-30T15:33:00Z")
> [@jjonas](#): > > that outdated (11+ years old) and poorly drawn graphic. @zupright may be interested in this thread. ---
**Author:** ![ehochban](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/ehochban/32/250901_2.png) [@ehochban](https://forum.nachi.org/u/ehochban)\ **Post date:** [June 30, 2026, 3:35pm UTC](https://forum.nachi.org/t/clarification-on-a-roofing-question/268750/4 "2026-06-30T15:35:39Z")
👍 _ **least 24 inches** _ ---
**Author:** ![lkage](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/lkage/32/347658_2.png) [@lkage](https://forum.nachi.org/u/lkage)\ **Post date:** [June 30, 2026, 4:33pm UTC](https://forum.nachi.org/t/clarification-on-a-roofing-question/268750/5 "2026-06-30T16:33:45Z")
And the 24” runs in horizontally, not up the angle of the roof. ![000](https://global.discourse-cdn.com/internachi/original/4X/6/1/9/619fd111fd24bf4e66157b7640e4cc98fd690cc1.jpeg) ---
**Author:** ![wjones18](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/wjones18/32/397367_2.png) [@wjones18](https://forum.nachi.org/u/wjones18)\ **Post date:** [June 30, 2026, 5:40pm UTC](https://forum.nachi.org/t/clarification-on-a-roofing-question/268750/6 "2026-06-30T17:40:34Z")
If you look at the diagram, it is not showing 18-24" from the roof eave. Underlayment is typically 36" wide. ---
**Author:** ![zupright](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/zupright/32/301800_2.png) [@zupright](https://forum.nachi.org/u/zupright)\ **Post date:** [July 14, 2026, 8:44pm UTC](https://forum.nachi.org/t/clarification-on-a-roofing-question/268750/7 "2026-07-14T20:44:21Z")
Yep, this could use a redraw. Thanks guys!