Closed Cell Foam Tips and Budget Suggestions

Are You Considering Closed Cell Foam For Your building Insulation?

Foreword by Ian Thompson, Editor

Closed-cell and open-cell foam are two common types of insulation used in housing construction. They differ in their physical properties, cost implications, installation methods, and sustainability.

Closed-cell foam insulation is denser and provides a higher R-value (about 6-7 per inch), offering superior insulation against heat transfer. It also imparts some structural strength to walls and resists water and air infiltration, making it a good choice for colder climates or flood-prone areas. However, closed-cell foam is more expensive than open-cell foam and requires professional installation due to the chemicals involved and the precision required in its application. Despite its higher insulating properties, closed-cell foam often has higher off-gassing levels, which may raise indoor air quality concerns, and it’s generally less sustainable than open-cell foam.

On the other hand, open-cell foam insulation offers a lower R-value (approximately 3.5 per inch) but is more breathable, allowing moisture to pass through, which can be beneficial for interior walls and attics in milder climates. It is less expensive, making it a more economical choice for large insulation projects. Open-cell foam is less dense and easier to work with, but professional installation is still recommended for optimal performance. It generally has lower off-gassing levels and is considered more environmentally friendly, often using water as a blowing agent instead of high Global Warming Potential (GWP) hydrofluorocarbons.

When compared to natural insulators like wool, both closed-cell and open-cell foams offer higher R-values, meaning they provide better insulation per inch of thickness. However, wool insulation is a sustainable and renewable resource, with lower environmental impact during production and end-of-life disposal. Wool also naturally regulates moisture, absorbing and releasing it as needed, which can improve indoor air quality and comfort. However, wool insulation can cost more than open-cell foam and can be similar to or slightly less than closed-cell foam, depending on the product and installation costs in your area.

In terms of ease of installation, both types of foam insulation require careful preparation and are best installed by professionals due to the need for special equipment and protective measures. Open-cell foam, being less dense and more expansive, can be easier to install in irregular spaces but still requires expertise to ensure an even spread and proper coverage. I’ve used closed cell foam in limited amounts in areas where we have to punch services through an external envelope, but it’s messy and sometimes difficult to see areas where holes have been missed. For me closed-cell foam has its place but I prefer to use more sustainable and healthier insulative products if I can.

Matt Risinger’s short video presents a good overview of the two insulation types and their appearance. Over to Matt.

Closed Cell Foam Tips and Budget Suggestions

Going behind the scenes on this spray foamed house with some tips and tricks for using closed cell spray foam to the maximum!

Video Transcript:

Hey guys, coming to you from my LVL-framed house. Last week, we did a video here talking about the benefits of closed-cell foam and why we use it on this house. But on today’s video, I want to take you behind the scenes and show you a couple tips or tricks for using closed-cell foam to the maximum and also a couple of tips on how to get the best bang for your buck. So let’s get going.

We’re gonna start here in the garage space. Now, as typical for a lot of houses that are two stories, they’ve got a bonus space above this garage. We’ve got a big workout room up there, and that’s where you can really see the benefit of that closed-cell foam. We’ve got two inches up there, and you can see it sticks tenaciously to that Advantech deck. And we’ve got upstairs the perfect application for closed-cell foam.

Two inches is all I need to meet code in my climate zone. That’s basically our R14 up there. If you’re in a northern climate, you’re gonna want to add more insulation up there. You probably have an R21 necessary for a floor. But here, we only need our R14. That’s a perfect use for closed-cell foam.

But now, as we walk from the garage and up these steps into the house, a couple of things you notice here. Number one, I’ve got these massive bats sitting around. We have not installed these yet. Stay tuned for a future video on using Rockwool bats for a flashing bat system where we’ve used closed-cell foam in the walls, and then we’re gonna finish that off with some bats. Now, Rockwool changed their name. That’s why their old logo is on here. They’re not called Rockwool, not RockSoul.

The next thing you’ll notice, though, is look here. I’ve got some drywall already hung in the garage. Why is that? We’re not in that stage quite yet. And here, you can see just a little bit of a teaser as to why. Look at that spray foam coming around the drywall right there. Let’s walk into the house from these garage steps, and I want to show you the backside of this drywall.

Okay, now when you get to the top of the stairs, look up, and you’ll notice that we’re totally encapsulated. And where I am here, this is the door in this space between the house and the garage. And this is basically the thermal envelope to the house. This is also the air envelope to the house. Out here is garage, and in here is heated and cooled house space. And now you can see why we put that drywall up.

As we come around here, we’re now in the kitchen space on the backside of the drywall. We sprayed that closed-cell foam. As long as we have one inch of closed-cell foam, we’ve got a total air barrier. So we could have just one inch here. We chose to go two inches everywhere. And remember that outlet I showed you on the other side? Here’s another outlet right here. These are probably some switches turning on some lights in the garage. Look at that. Totally encapsulated with that closed-cell foam.

Why do we do that? What’s the big benefit? We want to make sure that our garages are totally encapsulated and sealed off from the rest of the house. Nothing good happens in the garage from an air quality standpoint. We’ve got fumes from your car. We’ve got maybe gas storage out there or paint storage. We don’t want any of those fumes in the house.

We’ve also not located any ducts or any HVAC out there. We want to isolate 100% that garage air from the house there, and that’s a great way to do it. Now, look up in the ceiling up here. You’ll see something a little different. We’ve got that cool curved ceiling going on in the kitchen. Check out my Instagram feed to see some behind-the-scenes on this house. This is the hashtag LVL framed house. But as we get above that curved ceiling, you notice we’ve got a puffy insulation up there. That’s open-cell foam. So what we did was we actually did two types of spray foam on this house. Two inches of closed-cell pretty much everywhere, walls and roof. But then we came back in quite a few spaces and used open-cell foam. And this is a great place to see why.

Above the ceiling here, I’ve got an attic space, and there’s some attic decking for an attic above here. But I could not have gone in very easily with traditional batt insulation in this space up there. But when I use the open-cell, again, because that open-cell is going to stick, it’s sticking to this closed-cell, it’s sticking to the framing. We’ve been able to get that full-depth insulation we need in there. So in the roofline and the band joist area, we came in with seven inches of open-cell foam on top of the two inches of closed-cell foam. Now, remember from the other video, closed-cell foam is about 6.9, what’s called R7 per inch. So two inches is going to net us R14.

And then on top of that, in those ceiling spaces, we ran seven inches, plus or minus, of open-cell foam. Open-cell foam is about 3.5 per inch of R-value. So if you add those two together, we’re just shy or right around R40 in total for the roofline and for our band joist areas. Let’s go up. Let me show you one of the attic spaces.

Okay, we’ve actually started installing a few areas already on that Rockwool. These are not for insulation purposes, actually. These are for sound isolation. But if you come back here, we can start to see a couple of the attic spaces. Take a peek into that attic above you here. Look at that. That’s beautiful.

Now, you can see where we’ve got full-depth insulation. We’re almost 10 inches of insulation between the two of those open and closed-cell. And if you look to your left right here in this space, you’ll see where we’ve got a little bit of missing insulation. That’s because we’ve got an attic back there. It’s basically conditioned space on the other side. And that’s how you can see how we’ve totally encapsulated those 2×6 rafters. So I’ve got several, you know, 4 inches, let’s say, of foam on top of those rafters, very, very well-insulated attic space. Take a peek into this one too. You’ll notice all the ductwork. Now, all the HVAC, it’s all within the thermal envelope of the house. Nothing is outside of the air-conditioned space in this house. It’s really a great way to go, guys. Thanks for joining me. Big thanks to our sponsors on this series of spray foam videos. I’ll link to those guys in the description below. Otherwise, we’ll see you next time.

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External Youtube related post: Using SprayFoam – Closed Cell and Open Cell Spray Foam