What Should I Use?: Episode 6 - Roofing Assembly

In this episode of "What Should I Use?" hosted by Jake Bruton, we dive deep into roofing, exploring the intricacies of roofing codes, with a focus on metal roofs and the importance of durability. Jake begins with a key excerpt from the IRC 2021 on roof drainage, emphasizing its relevance in expansive soil areas. The discussion shifts to the pros and cons of asphalt shingles versus metal roofs, and the cost-benefit analysis of each. With special guest Peter Yost from Building - Wright, we delve into the specifics of unvented attic assemblies and the significance of vapor diffusion ports in maintaining roof integrity. Jake also shares insights on fortified roofing standards and why choosing the right materials can significantly impact the longevity and durability of your roof.

This episode is sponsored by Sharkskin and Sheffield Metals.

Subscribe and follow my Podcast on Apple or Spotify!

Sign up for our twice-weekly newsletter:

To sponsor a video or advertise with us visit:

[jerryminyard]

The sharkskin owner is awesome. I am a DIY homeowner and he called me back/texted with answers to my questions.

[aweisen]

Haha, the thumbnail made me think they made a zip system dumpster…

[jonathansage]

The build show only ever does up to climate zone 3. I'm in climate zone 4. I went ahead and used a conditioned attic and vapor diffusion port anyway. Joe Lstiburek has stated that he thinks the assembly will work in colder climate zones. He also came up with the idea when confronted with failing roofs in Alaska. I just wish the build network would do more than hand wave at colder climates.

[LegacyViewsICFhomeBuild]

I’m installing an unvented roof assembly on my 5 story DIY 48’ tall icf home that I am building. This information was super helpful because I will be using many of these details.

The mechanically seamed metal roof will be a critical part of my house because I will be installing 20, 000 kilowatts of solar on top using a clip system and I will have a roof top deck on the 1.5/12 pitched roof that has epic views of the mountains surrounding our valley.

[genes.]

In the various roofing assemblies, here's the part I don't get: how are the penetrations for the roofing material attachment sealed? In this case, it would be the metal mounting clips - they have to be screwed through every layer (membrane, dimple sheet, zip sheathing). Here, the dimple sheeting permits air movement but also provides drainage for water that might get under the metal roofing. Wouldn't that water potentially get into any of the screw penetrations? Or is this amount of water truly negligible, so who cares??

[machickman]

I would love to see a video on what should I use for exterior insulation

[GoldenBirdBrain]

Absolutely, please do a cold climate follow up to this!

[markstipulkoski]

Nice, but I need you guys to wake up Steve Baczek from his nap and give me a Big Red explanation of this assembly!😂✌️

[r.j.bedore]

Jake, I am thinking of building my first house, and since I live in climate zone 6 I would be very interested in a follow up video that covers cold climates. I have been watching a lot of videos from you, Matt, Steve, and a few others here on YouTube. I don't know if my budget will support all of my ideas, but what I would like to do is build the house with no overhangs (what Matt calls Monopoly framing) using 2x4 staggered stud construction at 24 inches on center with 3/4 inch plywood for both the wall and roof sheathing, then apply a continuous fluid applied WRB. On the exterior walls I would have 2 or 3 inches of Rockwool comfortboard 80 (code here now requires R10 of continuous exterior insulation for 2x4 (R13) walls or R5 on 2x6 (R21) walls), then vertical 1x3 or 1x4 furring strips fastened through the Rockwool and sheathing to the studs with a bug screen and correvent at the bottom for a rain screen, with either fiber cement board or thermally modified wood siding.

Then on the roof I would put a self sealing underlayment and/or ice and water shield on top of the fluid applied WRB, followed by butyl tape along where the rafters are (also at 24 inches on center). I would then put 4 inches of Rockwool comfortboard 110 (or their fiberglass and foil faced flat roof product if I can find and afford it) with pressure treated 2x4 furring strips put on top inline with the rafters, with the butyl tape sealing the screw penetrations through the roofing membrane and into the rafters. These 2x4s would extend out past the walls, with additional timber being ledgered onto the wall on top of the exterior insulation and extending out to meet the 2x4s from the roof to create the eaves and soffits. Correvent would be placed between the 2x4 furring strips at the edge of the roof insulation to allow air to flow from the bottom of the walls to the ridge vent at the top of the roof. A typical radiant barrier roof sheathing product would then be attached to the 2x4 furring strips, onto which a metal roofing would be fastened.

On the inside of the house, the staggered stud exterior walls would have enough of a gap between the planes of studs that plumbing and electrical wires could be run between them. I would insulate the cavities between the exterior most 2x4 studs of the staggered stud walls, then put a smart vapor retarder (such as intello+) against those studs. These would keep me from having to try and air seal around all of the electrical boxes, and I would only have to worry about sealing penetrations that went to the outside. After all of the electrical and plumbing is completed in the exterior walls, I would put in batts of Rockwool between the interior studs of the staggered stud walls (assuming budget allows for it), then hang drywall or wood cladding.

I think I will cover all of my bases with this setup to meet code and have a long lasting, comfortable house, but is there anything from your experience that jumps out as a potential problem? Also, thanks for all of the great information you are providing with this video series.

[sawdustadikt]

The money I would happily pay, for a legit consultation service for this stuff. Thanks for effort and time you put into this video.

[Bradimus]

We did get Certainteed Landmark Climateflex shingles in Minnesota after hail damage last year. They're class 4 hail rates and our homeowners insurance is actually providing a discount for what was a small upgrade price. Though, if I build a new home steel all the way.

[dougfraser]

Very nice presentation. Would love to see an update for climate zones 4A and 5A

[garster]

We got a metal roof 2 years ago, love it. Great for solar too. Buy once, cry once.

[danvining]

That's exactly the roof layout I was planning, thanks for the verification. I probably won't use zip so I'm planning SA on ply, then dimple. Never thought of adhering SA to dimple

[RJ-ccfz]

You didn’t mention a hybrid roof for climate 3.. at least R5 polyiso sheets on top of the decking and fluffy in the rafter bays. Supposedly this stops condensation from forming on the decking because the polyiso keeps the dew point temp correct. So no need for diffusion port and no need to vent from eve to ridge. Please correct me if I’m wrong.. However you can’t simply add more and more fluffy without adding more polyiso to the top side of the decking..

[bakerz]

Is that a different sheathing at the ridge?

[justinmanship]

How is that ridge cap attached with 12” of roof decking cut out and a vapor port installed? Don’t see how you’d attach the Z bar.

[jybuis]

@11:48 man Jake gets kinda nervous when Peter takes a swipe at Jeff Baczek, from that point on he's a little wound up.

[jameschupp]

So it sounded like you said that you could use closed cell Spray foam in that cathedral set up between the rafters

And I think I heard you say that you were thinking moisture will travel through that

I’m just wondering why you would say that

[dlg]

I'm in climate zone 5 where it gets down to single digit temps in winter and up to upper 90s and humid in the summer I'm planning a full remodel of my 1962 built ranch with full basement. I'm going with a high performance unvented enclosed vaulted roof, but I will also be adding exterior insulation on the entire envelope. Figuring out the proper order of all the different layers for my climate is what I need help with. My idea of the perfect unvented roof assembly (no attic) would be - 24ga metal roofing, peel and stick WRB, 5/8 plywood, 1x3 strapping as vent gap, 2 layers of 2in foam board insulation with staggered seams, peel and stick WRB, 5/8 plywood, 12in vaulted roof trusses (dense pack cellulose in truss cavity), 1x3 strapping for service cavity, 5/8 dry wall, interior living space. It's basically a homemade SIP. Not sure I need the upper WRB layer, might skip that. This would be an expensive roof assembly, but it would be extremely efficient (roughly R-75) and have bullet proof durability. The exterior wall assembly will be pretty much the same, excluding the outer layer of plywood. My goal is a maint free house that achieves ultimate comfort. Thoughts?