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The Difference Between Residential and Commercial Spray Foam Job
What’s different about doing a commercial job with spray foam?
Well, typically, on commercial work, it’s a lot more industrial, meaning the specs are usually a lot more robust than residential.
When you say robust, what do you mean? I’m not sure I understand.
Well, the job in Culver City that we did.
So this is the one… oh that’s the video.
The tip like this one right here.
That looks like our work.
Yup. It’s 4 inches on the walls where typically, residential has 2, at the most 3.
So, why more? Why 4 inches?
Because commercial buildings typically build them in a way that they can handle a lot of people. They’re just built a lot more sound. Typically the specs on commercial work are a lot more intense. This is the nature of the business on commercial work. More money spent.
I imagine there’s a lot more surface area on a commercial building to…
Typically, yeah. I mean I’ve done some small commercial jobs as well. A lot of commercial jobs we insulate on top. They’ll want me to roof system and foam roofs are very typical on a commercial.
So when you say insulate on top, you’re talking about the top layer of the roof would be insulated.
On top of the roof, yes.
So what does that do to people being able to walk on it.
They can walk on it. There’s no problem with that. It’s very durable.
Is spray foam let just at the top surface area or is something put over on top of the spray foam?
No, there’s an elastomeric roof coating that’s sprayed on top of the foam.
Is that part of what you do?
What’s it called? Elasto-something?
Elastomeric roof coating.
What is that? What does it do?
It’s an acrylic coating that has a reflective value, preserves the foam. The foam can’t tolerate direct sunlight. It just fails or burns up. You have a protective coating on top of that, which is a water-tight seal. A lot of times depending on the building that, let’s say like it’s a restaurant or something, and they want to do a lot of woodwork on the ceiling. We’ll insulate the roof on top. We’ll put, for instance, 4 inches of foam on the roof, and then we’ll coat it with the elastomeric roof coating. So not only they got an insulation job, but they also got a new roof system as well.
So this would be an example of that in process.
This doesn’t look like it’s spray foam.
That’s spray foam. Yeah.
So how come it’s got squares like this if it’s spray foam?
The light colored material over what the guys are standing on, that’s the foam.
Oh, I see!
What the squares are, what that is, it’s called DensDeck, which is a fire-rated material, so you can have your fire rating and it’s screwed down with plates. That picture there though, it happens to be a residential roof.
Oh, I’m confused. This doesn’t look like a residential building because it’s flat.
It is. It’s residential.
So do you have any pictures of where you applied spray foam to a commercial project?
Yes. 7 Gables Real Estate building.
So this is a commercial one?
Right. So what are we looking at? Is this spray foam?
That is spray foam with the white coating on it.
So the white coating reflects the sunlight, UV, which stabilizes the spray foam underneath.
Yes, it protects the foam from the ultraviolet rays, and it’s a reflect coating which makes the building cooler inside.
So that’s a different one to this? So it’s kind of like a wall around it. This is the actual building. And that the…
That’s the port building. That’s a car port. And all those posts that are sticking up, they’ll have solar panels on them. So those are the stands to the solar panels.
So why would you apply spray foam to a car port? That’s not intuitive.
With all those penetrations going in, they needed a new roof system, so they hired me to do the building, so they just had me do the car port as well.
What’s the process? Is this something that goes down before the spray foam?
This is not new construction. This is an existing built-up roof system on there. Which is the hot tar roofing, and they have the rolls of roofing. And those rolls of roofing, you see those things every 3 feet. That’s the old roof underneath it.
Right. So you applied the spray foam directly to the black tar?
Right over the existing roof system.
First of all, that’s a layer of spray foam. And that’s how thick?
Yes. That’s 1 inch thick.
Oh, just 1 inch?
Minimum of 1 inch. And 1 inch is very typical now. When you do residential roof, 1 inch is common. When you do commercial roofs, an inch and a half is very common.
So if somebody was to ask about having spray foam applied to a commercial building like this, what would you recommend as against what is common?
I would recommend an inch and a half. It all depends on the condition of the roof system that’s on there. You have to inspect that early. A lot of times there’s rotten plywood in different roof systems, you have to take different things into consideration. What is very typical also, we have here, it’s called a cap sheet roof on top. And what you do first thing is that you first clean everything. Make sure that the existing roof is as clean as possible. And then after it’s clean, you spray apply the foam. And after that you get 2 layers of the white elastomeric coating.
Why an inch and a half? I mean down here you talked about 3 or 4 inches for commercial or 2 inches for residential. Why is it an inch and a half on the roof?
On commercial buildings, they typically want a more heavier duty system. Even when it comes to roofing or insulation. They typically go a step further and get a little better system in there, because you have a lot of people coming in and out of there. So they want something that’s going to last a little longer and do a little bit more for them.
Right. But I’m confused, because an inch and a half is less than 3 inches or less than 4 inches or less than even 2 inches when you do an insulation in a home. So it sounds like an inch and a half is not as good.
If you’re talking just the roof system, you have to have a minimum of 1 inch. That gives you a little bit of R Value, but if you’re looking for an insulation system and a roof system, now you’re talking something different. You have to have your R value on top of your roof. Then you’ll have to add 3 inches or 4 inches if you want to have your R Value in the insulation. If you just want a roof system, and that it, and it’s insulated underneath, you have to a minimum of 1 inch.
Right. Now I understand. So when you say a roof system, it’s just an alternative surface that’s going to repel water and keep the roof intact.
So what you’re doing when you’re saying 1 inch to 1 and a half inches is okay if the requirement is just to keep the roof sound. But if you want the R Value to be improved, then you need to go to 3 or 4 inches.
Glendale Commercial Spray Foam Project
We did a job out of Glendale Boulevard in L.A., and it came out really nice. It got 5 inches. It’s a good example. It’s a sound studio. So they needed extra insulation, but they wanted to show the wood ceiling. So they insulated it from the roof. So they needed a roof system plus they needed insulation. That’s what you call a summer bell roof system. That’s the shape. It looks like a dome. It’s called a summer bell. What it does is all the water rushes towards the air pit walls and then it drains towards the corner there. It’s a sound studio in Los Angeles, and they wanted to see the stained wood underneath. So they had me do the insulation. They wanted to insulate it from the roof, on top of the roof, and they needed a roof system at the same time. So I put 4 and 3 quarter inches, which is an R30. Now they meet code. And they don’t see the insulation underneath. They see all the natural wood.
Okay. Let me just try and understand. So what you’re saying is that on the inside of the sound studio, they can see all the wood that is the underneath the roof. So that they’ve got something that looks visually cool… by insulation… the look of the roof. So what they’ve done is they’ve applied insulation to the outside of the roof. And in order to get the R value and meet code for the roof system itself, in terms of its integrity and waterproof-ness, to get all of that you’ve gone to 4 and 3 quarter inches to get R30.
So again, on this one, the process is the original roof is there, and you just went straight, oh you cleaned it up and you just went over it with spray foam, or did you do something else to it first.
That’s it. We cleaned it up. Cleaned it up really good. And we sprayed it on top of the original roof system, and then one layer of coating. Let that dry for 36 hours. And then we put a second. We’d do a total of 3 gallons per hundred square feet of coating.
So I imagine compared to a black tar style roof, going to white, reflective white like that, on top of insulation, must make a huge difference to the insulation value of the roof.
Huge! Huge! On top of the R value and the air ceiling of the foam, the reflective value you get off this white roof system is tremendous.
So this is open cell or closed cell?
This is closed cell foam. The roofing foam is a little bit different blend.
Oh is it?
It’s a different blend. It’s the closed cell foam for insulation that’s a 2 pound density. The density on this is 2.8.
So that makes it strong enough to walk on?
So where’s regular closed cell strong enough to walk on?
That’s an example of a commercial project where spray foam is applied to the outside surface of the roof. So roughly what, how big is that roof? What kind of scale are we talking about?
10,000 sq. feet.
Roughly, how long does a job like that take?
I think it took us a week to do from start to finish. If you look at it Tim on top of the purple wall, see that metal coping that’s attached to the top of the wall. Right there. That grey, looks like a cap on top of that wall. Goes all the way across. This is an example because we’re a construction company with a general contractor’s license, we’ll take on other trades. Typically, that is a sheet metal contractor’s job to come behind us and put this coating on. We wanted to have that fabricated and we install it for them.
So 10,000 sq. feet about a week to do. So that’s a roofing system. Can we look at some of the commercial jobs where you’re putting the spray foam to the inner walls?
Target Distribution Center Spray Foam Insulation Project
Let’s go to Target. This is the Target distribution center for Southern California. Huge building in Colton. Out in the inland empire there. And this is a loading dock. A metal siding. The sun would hit that thing and that metal, that whole loading dock inside there, which is cook. The loading dock itself is outside of the conditions space. They needed somehow to make that thing cooler in the summer time. So we sprayed 2 inches. All they wanted me to do was to knock down some of the heat that’s penetrating that siding. So we went along and did the entire side of the whole loading dock.
So that’s regular closed cell foam?
That’s regular closed cell 2 pound foam. He’s applying it off a scissor lift. You know that loading dock is a huge building. 45 feet tall.
So in this case that we’ve got 2 inches of spray foam to lower the cost of the wall that’s in direct sunlight. To lower the heat transfer on a metal wall that’s in direct sunlight. Kind of trade-off between the heat and the cost and doing 2 inches and getting good insulation value in return.
What would be the R value of that then?
Well the R value is a 13, but you’ve got to remember Tim, the spray foam is not about R value. It’s about air sealing. Because what R value is… you have different… like R 13, you have R19, and you have R 30, and so on. And more R value you have… what that means is that heat transfers from the outside of the building… it transfers into the insulation. And the longer it takes to get that insulation to work, it’s 100% all of the heat load. Then that heat transfers inside of the building. So the longer it takes for the insulation to get a 100% heat load is a higher rating. Like if it takes 2 hours as opposed to 4. 4 is a higher R value. It takes longer for the heat to penetrate the insulation. When you’re talking spray foam. If you have a minimum of 2 inches, you have air seal so R values… in a penetrate. It doesn’t load up and enter the building. That’s why R value isn’t important in spray foam. It stops the heat from coming in.
So let me say it if I understood it correctly. Another way of saying that might be, although the R value is important and helps with insulation, one of the secondary benefits of spray foam is possibly more important than the R value, is the fact that it seals the building so that you don’t get air coming through, and being transferred directly into the building.
Regular forms of insulation don’t do.
Correct. Yeah. It stops the heat from coming in. So the reason why we have our different R values is because the city inspectors and the city codes aren’t up to speed with spray foam. If you ever tried to change a code, especially in California, it’s next to impossible. So they have these tidy codes that are in place. For instance, in a wall they say, the inspectors have to see an R19. That’s 3 inches of foam. Even though 2 inches would be more than enough. 2 inches would probably perform like an R38 or R50. It just does not enter the building. There’s no way you’re going to be able to change the code.