# Metal Roof Decking Question **URL:** \ **Category:** Exterior Inspections\ **Created:** [May 14, 2008, 12:05am UTC](https://forum.nachi.org/t/metal-roof-decking-question/28205 "2008-05-14T00:05:10Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![ckirby2](https://avatars.discourse-cdn.com/v4/letter/c/47e85d/32.png) [@ckirby2](https://forum.nachi.org/u/ckirby2)\ **Post date:** [May 14, 2008, 12:05am UTC](https://forum.nachi.org/t/metal-roof-decking-question/28205/1 "2008-05-14T00:05:10Z")
Haven’t done a lot of metal roofs and so hoped someone could answer a couple questions for me. Did an inspection today on a house built in 2006 that had a metal roof. While in the attic, I noticed that there was no plywood or OSB sheathing/decking between the rafters and the metal sheets. Is this allowable/correct? All the metal roofs I have seen have had some sort of decking, but then again, most of those roofs were installed over an already existing roof. Also, there was a vent pipe that didn’t go through the roof. I assume that is incorrect for a metal roof as it is for a shingle roof. Any help would be appreciated. ![Roof-Attic View.jpg](https://global.discourse-cdn.com/internachi/original/3X/5/9/59122373fec1ed838727d33723dbfc4701444d10.jpeg) ![Roof-Attic View.jpg](https://global.discourse-cdn.com/internachi/original/3X/5/9/59122373fec1ed838727d33723dbfc4701444d10.jpeg) ![Pipe.jpg](https://global.discourse-cdn.com/internachi/original/3X/a/d/ad6abf21fcd6f889dc3bbe85451cf99b5e4106f9.jpeg) ---
**Author:** ![jmckee](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jmckee/32/211009_2.png) [@jmckee](https://forum.nachi.org/u/jmckee)\ **Post date:** [May 14, 2008, 1:00am UTC](https://forum.nachi.org/t/metal-roof-decking-question/28205/2 "2008-05-14T01:00:46Z")
the purlins support the metal roof without sheating Clint, but You are right about the vent…that is just plain wrong…IMO…jim ---
**Author:** ![ckirby2](https://avatars.discourse-cdn.com/v4/letter/c/47e85d/32.png) [@ckirby2](https://forum.nachi.org/u/ckirby2)\ **Post date:** [May 14, 2008, 2:05am UTC](https://forum.nachi.org/t/metal-roof-decking-question/28205/3 "2008-05-14T02:05:26Z")
Thanks, Jim. Is that a typical metal roof installation for a new roof, i.e., with no decking/sheathing? If so, is it done that way because it is cheaper and/or faster? Just curious… ---
**Author:** ![jmckee](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jmckee/32/211009_2.png) [@jmckee](https://forum.nachi.org/u/jmckee)\ **Post date:** [May 14, 2008, 2:12am UTC](https://forum.nachi.org/t/metal-roof-decking-question/28205/4 "2008-05-14T02:12:42Z")
Yes to all of the above as far as I know…I’m sure no expert , but this is the way i see them on new construction…jim ---
**Author:** ![mcyr](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mcyr/32/173319_2.png) [@mcyr](https://forum.nachi.org/u/mcyr)\ **Post date:** [May 14, 2008, 11:06am UTC](https://forum.nachi.org/t/metal-roof-decking-question/28205/5 "2008-05-14T11:06:46Z")
This link may help a little. [http://www.bestbuymetals.com/pdf/tuff-rib-installation-guide.pdf](http://www.bestbuymetals.com/pdf/tuff-rib-installation-guide.pdf) Marcel 🙂 😃 ---
**Author:** ![badair](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/badair/32/166699_2.png) [@badair](https://forum.nachi.org/u/badair)\ **Post date:** [May 14, 2008, 12:45pm UTC](https://forum.nachi.org/t/metal-roof-decking-question/28205/6 "2008-05-14T12:45:51Z")
> [@ckirby2](#): > > Haven’t done a lot of metal roofs and so hoped someone could answer a couple questions for me. > Any help would be appreciated. In your photo there appears to be a lot of eave daylight. That usually is an indication that the profile vent/stop material was not installed, is displaced or has failed. Vermin, insects and birds can become problematic when this feature is omitted. This is not necessarily a defect, more of a nuisance issue and advising the client along with a note in the report…avoids call-backs :roll: HTH ---
**Author:** ![ckirby2](https://avatars.discourse-cdn.com/v4/letter/c/47e85d/32.png) [@ckirby2](https://forum.nachi.org/u/ckirby2)\ **Post date:** [May 14, 2008, 11:16pm UTC](https://forum.nachi.org/t/metal-roof-decking-question/28205/7 "2008-05-14T23:16:48Z")
Thanks fellas. That was a big help! ---
**Author:** ![kshepard](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/kshepard/32/59504_2.png) [@kshepard](https://forum.nachi.org/u/kshepard)\ **Post date:** [May 17, 2008, 2:34pm UTC](https://forum.nachi.org/t/metal-roof-decking-question/28205/8 "2008-05-17T14:34:41Z")
I see a lot of metal roofs and have never seen one installed without roof sheathing. According to [this link](http://www.expertvillage.com/article/1639_metal-roofing-installation.htm) it depends on the product. Most metal roofing is not very thick. Did you walk the roof? I would definitely call out the lack of a membrane. ---
**Author:** ![jkogel](https://avatars.discourse-cdn.com/v4/letter/j/e47774/32.png) [@jkogel](https://forum.nachi.org/u/jkogel)\ **Post date:** [May 17, 2008, 6:18pm UTC](https://forum.nachi.org/t/metal-roof-decking-question/28205/9 "2008-05-17T18:18:31Z")
> [@kshepard](#): > > I see a lot of metal roofs and have never seen one installed without roof sheathing. According to [this link](http://www.expertvillage.com/article/1639_metal-roofing-installation.htm) it depends on the product. Most metal roofing is not very thick. Did you walk the roof? I would definitely call out the lack of a membrane. Could this house be a converted shed? Up here in wet country, on a closed-in dwelling with heat, some kind of sheathing would be recommended, and even 15 lb felt is better than nothing. But just tin on strapping is pretty common for sheds and workshops with lots on open air under them. Makes it easier to find the leaks after a windstorm! 😃 John Kogel www.allsafehome.ca