Selecting Metal Panels Based on Roof Slope Podcast

Lexi: Hi everyone, and welcome to another episode of Metal Minutes by Cornerstone Building Brands. My name is Lexi Edwards, and I’ll be your host today. With me I have Jason Allen. He is the Research and Development Manager from MBCI. Jason, how are you doing today?

Jason: I’m doing great. How are you?

Lexi: I’m doing well. So today, Jason is going to be giving us the scoop on selecting metal panels based on roof slope. So that’ll be our topic today. So I guess what I want to start with, Jason, is what is a roof slope?

Jason: So your roof slope is going to be some kind of a pitch on your roof structure. And typically, it’s going to be like 3 on 12, a quarter on 12, a half on 12. And then sometimes you may see it in a degree of a slope, but typically you’re going to see it, like 3 on 12. And basically what that means, the first number is the vertical rise that it goes up in 12 inches. So it’s going to rise three inches in 12 inches. So that’s what the 3 on 12 stands for. So when you get a lower slope, like half on 12, it’s only going to rise a half an inch for every 12 inches. So that’s how you determine the roof slope.

Lexi: So the higher the number on top, the steeper the slope?

Jason: That is correct.

Lexi: Got it. Okay, so what’s the difference between a low slope and a steep slope? What’s the ratio difference?

Jason: So basically, if you want to consider something that’s low slope, it’s going to be 3 on 12 or less, and then steep slope is 3 on 12 or greater. So that’s how we determine a low slope versus steep slope.

Lexi: Okay. So getting into how we are going to actually select our metal panel based on our roof slope, what are some of the driving forces behind selecting those metal panels?

Jason: So the building code, IBC, the International Building Code, it does give you some indication of how you’re going to determine what panel you’re going to use for a specific slope. So in the IBC, it’s under section 1507.4.2, and it gives you some guidelines. There’s three different ones. So when you go through the building code, it says the minimum slope for a lapped, non-soldered seam metal roof without applied lap sealant is 3 on 12. So, that would be a good example of that. That would be like a through-fastened roof. So it would be like our Stormproof panel, or 5V Crimp, because there’s no mastic in the side lap of that. So you have to be 3 on 12 or greater to use that product.

Jason: The next one would be the minimum slope for and lapped, non-soldered seam with lap sealant. All right, so that’s going to give you a minimum of slope of 1/2 on 12. So you can’t go below 1/2 on 12. And some examples of that would be like our PBR panel or 7.2 Panel. So when you install that through-fastened panel, there’s a side lap, and you’re going to put sealant in there. So that’s how that’s going to apply to that.

Jason: And then the last one, the minimum slope for a standing seam roof panel is 1/4 on 12. So it’s going to be mechanically seamed, or it’s going to be like a snap-lock system, but there is mastic in the female leg of that panel. So with that, you can use a 1/4 on 12.

Lexi: So those are just minimum slopes, right? So it can be steeper than those?

Jason: Yeah. So we do have some panels that are actually a steeper slope than what, what it calls out in the code. It just depends on what the product is.

Lexi: Okay. So going back to the code, you said it was IBC. What does that stand for again?

Jason: The International Building Code.

Lexi: Okay. So is that an industry-wide standard?

Jason: Yes. I mean, most counties in the US are going to use the IBC building code or they may reference ASCE 7. So it’s another code that you’re going to go through. So, those are the main two that they’re going to reference.

Lexi: Okay, got it. So we talked about the building code, and how we have to apply by those standards. Do the panels themselves have different minimum slope requirements?

Jason: They do. So I’ll touch on our standing seams, and I’m going to talk about three different ones. So we have our Double-Lok panel. So, it’s a 24 inch wide panel. It’s trapezoidal. So the minimum slope is 1/4 on 12. And that’s also a three-inch tall panel. And then we have a SuperLok panel or a BattenLok HS panel. That panel is two inches tall, and it’s vertical leg. So the minimum slope for that is 1/2 on 12. And then we also have another standing seam, but it’s a snap-lock panel system. It’s minimum 3 on 12. So we do have some different products with minimum slope requirements. So you really need to get with a salesperson to make sure that you’re meeting the minimum requirement based on the roofing product that you’re looking at.

Lexi: Okay. So we’ve got codes that require minimum slopes for certain panels. We’ve got the panel itself that requires certain slope requirements. Do applications require different ones, or now are we getting into the personal preference?

Jason: Sometimes it depends on what your substrate is. So again, I mean, you really need to get with your salesperson or a technical person to make sure that you’re meeting their requirements for our roof panels.

Lexi: Alright. So let’s talk about benefits. So starting with a low slope roof, what are some of the benefits of a lower slope?

Jason: Typically for a lower slope, it may just be a gable building. It’s going to be very basic. You’re going to have less expense to the contractor. You’re not going to have as much accessories or trims. And then typically, commercial buildings are going to be considered low slope. And when you get to residential, it’s going to be more a higher slope.

Lexi: Okay. So going back to what you said about it being less expensive, how is it less expensive?

Jason: So it’s going to be less expensive, because if it’s a simple gable building, you’re going to have less components. So you can get up there, and you can sheet the roof a lot faster. Because, for example, if you have a lot of hips and valleys, you’re going to have to do a lot of field cutting, add a lot of other accessories to build that application for the details.

Lexi: So you had mentioned that commercial roofs are the most common for low slopes.

Jason: Yes.

Lexi: Is that for any particular reason?

Jason: Typically, they just want a big area with a small roof. If you get a high slope on a bigger building, it’s going to get real tall. And then you’re just going to have to put a lot more framing material on it, and it’s going to increase your costs.

Lexi: Okay. So moving on to a more steeper slope, what are the benefits of a steeper slope?

Jason: Well, with a steeper slope, if you’re in high snow areas, a lot of that snow will run off if it’s steeper. You’re going to have less ponding of water on the roof when you have rainstorms. With a higher slope, it’s just going to run off a lot faster. If you’re in a lower slope, you may have areas where the water may sit up there.

Lexi: So going back to where you talked about the snow loads and stuff. So what you’re saying is, steeper slope roofs can help in those areas where they get heavier snowfalls, because it would slide off the roof a little bit easier?

Jason: Yeah. It could slide off the roof, or it may not accumulate on the roof itself.

Lexi: Okay. So where do you see steep slopes being utilized?

Jason: More residential. You’re going to have steeper slopes in residential. You’re going to have a lot more hips and valleys. It’s going to be more of a cut-up roof. And then also, on steeper roofs, you want it to be aesthetically pleasing, because you’re going to be able to visibly see the roof panel.

Lexi: Okay. Let’s talk about installation of a steep slope and a low slope. What is the installation difference? Is it harder to install a steep slope?

Jason: It will be harder on a steep slope. You need to make sure that you have your safety equipment. And if it’s real steep, it’s more of a challenge to install the panel just because you’re not sitting flat or relatively flat on the roof. So there is a challenge with that.

Lexi: All right. Is there anything else that we should know about how to take slopes into consideration whenever we’re selecting a metal panel for a roof?

Jason: I think it’s more based on the aesthetics of what you’re looking for, for your roof slope. I would say again, if it’s a commercial building, you want to stay low slope. And if it’s residential, you want to try to go with a steeper slope, and then your roof panel is more visible to everybody out on the street or far away from the building.

Lexi: Okay. Sounds good. Well, Jason, thank you so much for joining us today. It’s been great getting your expertise in this area.

Jason: Well, thank you, Lexi. It’s been a pleasure talking to you about how to select your metal panels based on roof slope.

Metal Minutes podcast shares insights from metal construction subject matter experts deep dive into trending industry topics. Learn from industry leaders with knowledge relevant to many different project types. This podcast episode was created by Cornerstone Building Brands, MBCI’s parent company.

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