Spray Foam Installation for Commercial Building Roof Systems


When we do the roof systems, you’ve got to remember it’s a monolithic roof system, which means there are no seams. There is nowhere that water can penetrate. Unlike your typical systems when you spray the foam on top of the cap sheet, all of those lines you see, those are the seams underneath the roof. Right, I see. So when you do hot tar, basically you’ve got seams everywhere. Whereas, when you do spray foam, there’s coating. There’s no seams anywhere.

Correct.

What’s the lifespan of something like this?

20 years.

Is there kind of a warranty on that?

Yeah. It’s a 10 year manufacturer’s warranty and 10 year labor warranty. If you want to have a spec job, and you have to pay for this. The manufacturer will spec the job. You’ve got to use a certain use a certain thickness of foam, you’ve got to use certain types. They’ve got several different types of coating. You can purchase extended warranties by the manufacturer where the manufacturer will stand behind it for let’s say 15 years or 20 years, or 25 years.

So the standard is 10 years but you can get it extended to 15 to 20 years.

Correct.

See those air conditioning units Tim? On this particular building, we didn’t have to do anything to the AC in this, because there were on curbs. Now what’s very typical on older buildings, they didn’t build curbs for the AC and it’s a stand on. All they have is they…

So when you say curbs, you mean like this platform that it’s on.

Exactly. Right there. They have curbs already, so it’s done correctly. On older buildings, they’ll have a steel frame that’s set on top of the roof system. And the AC unit will stand on. That’s a poor application. It ends up wearing up the roof system after a while, because of the vibration of the AC unit. And if it has those steel frames, what we’ll do is we’ll build curbs for the AC units to stand and we put a sheet metal cap on top of it to make it water tight. We lift the unit a couple inches using jacks. Sometimes we have to use a crane. But we’ll lift it up, we’ll slide the new curb, and the sheet metal pan underneath the AC unit, and then we’ll foam around it. When it comes to the air conditioning work, the duct work that enter the building, we’ll coat that as well. See the big white box that’s bolted next to the… right there! That’s the duct work that enters into the building.

Right.

We will seal that against the AC unit and we’ll also coat it. So that the cool air that is…

Oh, I see! So what you’re saying then is because there’s duct work, you’re going to actually seal and coat that with spray foam as well.

Right.

Which will improve the efficiency of the cooling system.

Exactly. So the cool air isn’t going out the seams and it’s not being heated by the sun, because it’s just sheet metal. We’ll add like half an inch of foam and do two coats of coating on top of there just to make sure the duct work is insulated. So the cool air stays cool going into the building. So that will help them save. And we did that on every building or residential house.

So you’ve mentioned residential a couple of times in terms of flat roofs. How often do you end up with a flat roof with an AC unit on a residential building? Sounds unusual to me.

No, no! It’s very common. I think because you live in Utah with the snow that you get, you probably don’t see as much. In Arizona it’s very common.

Well I know one of these…

Escondido new custom home.

That’s on the inside.

We did insulation on that as well.

On the outside. Oh there we go. So that’s the outside. You did the inside like we just looked at but also, you did this, which is putting spray foam on the surface of the roof itself.

Correct.

And that was in Arizona?

No, no. That one’s in Escondido. That’s in California.

Alright. So it’s not unusual for flat roofs like this.

No.

So what they’re doing is putting… this is spray foam that we can see here going on the surface.

Correct.

And did you apply this surface here? Is this a new construction?

Yes. It was new construction. And now spray foam only has a C fire rating. We have to add a fire barrier to the foam. So what we do is we screwed down a quarter inches of DensDeck

And that’s what these squares are here?

Yup. And we screwed that down with plates. So the screw head just don’t pop out, we have like three inch plates.

That’s these things.

Yup. And you screw that down on top of the plywood. And then you spray foam right on top. Now you have your fire rated roof system.

So what is DenDeck?

It’s a fire rated board. Fiberglass board.

Ah, ok. You applied all of this DensDeck fire rating, fire resistance, and then you applied spray foam over the top of it to seal it.

Yup.

Applied how much? What dense did you do on this one?

That was one inch.

And you would coat that as well?

Correct. Two layers of Elastomeric roof coating.

Again, it’s reflective and it helps seal and make the whole thing water proof.

Yes.

Everything that we’ve looked at so far has been closed cell.

Yes.

Do you ever use open cell on a commercial building?

For insulation? Yes.

So why would you use open cell on a commercial building? What circumstance?

It’s a lot cheaper and if they’re just looking for thermal and an air seal, they can save a lot of money by doing that. And as I remember, open cell is open for sound. In San Diego, we did a gym. It was aa work out gym and they wanted on their cardio area where they had loud music. And they didn’t want the people working out with the weights be disturbed by all the loud music going on, so they had me do the wall in between that with open cell foam because they wanted a good sound barrier.

So how did you do it then?

We did it eight inches thick.

Oh wow!

Yeah.

Presumably, when you’re going for the maximum sound insulation, you’re going to fill the cavity presumably, are you?

Yeah. Let’s say if it’s framed with two by tens, we usually take it out to the end. Get as much in there as you can.

So that’s the other component of commercial projects then is if sound is the main issue or the priority, then you might use open cell and fill the cavity to get the maximum sound insulation.

Correct.

It’s just not immediately obvious, I think, that a gym is necessarily something where sound becomes an issue, but that’s a good example of it I think.

Yup.

I imagine there’s going to be a lot if you got an office block near an airport or something like that. That might become a priority.

Yeah.

Or anywhere where there’s a lot of background noise and you want to insulate it.

A lot of sound studios in Hollywood and L.A, Beverly Hills, yeah.