If you’ve been researching spray foam for your Michigan home, barn, or crawl space, you’ve run into the same two terms over and over: open-cell and closed-cell. Here’s what they actually mean, minus the sales spin. Mid Michigan Spray Foam installs both, so we have no reason to push you toward either one. We just want the foam to fit the job.
The Short Answer
Both are spray foam. Both insulate and air seal at the same time. The difference is density, and density changes everything else: R-value per inch, how the foam handles moisture, how tough it is, and what it costs.
Open-Cell: Soft, Light, and Great Indoors
Open-cell foam is soft and spongy once it cures. It expands a lot when it’s sprayed, which makes it great for filling wall cavities and odd-shaped spaces. It’s the more budget-friendly of the two, and it does a great job quieting sound between rooms.
Where open-cell shines:
- Interior walls
- Sound control between rooms and floors
- Attic roof lines in many homes
One thing worth knowing: open-cell is not a vapor barrier. Where moisture is the main enemy, like a damp crawl space, it usually isn’t the right tool.
Closed-Cell: Dense, Tough, Higher R per Inch
Closed-cell foam cures hard and rigid. It packs more R-value into less thickness, which matters when you don’t have much depth to work with. It also acts as a moisture barrier, and because it cures stiff and bonds tight, it adds real rigidity to whatever it’s sprayed on, including metal building panels.
Where closed-cell shines:
- Crawl spaces
- Basement walls
- Pole barns and metal buildings
- Exterior walls
- Anywhere moisture, condensation, or strength is a concern
Which One Goes Where in Michigan
- Crawl space: closed-cell. Michigan ground stays damp, and you want a foam that blocks moisture.
- Pole barn or metal building: closed-cell, for condensation control and added rigidity.
- Interior walls and sound control: open-cell.
- Attic: either can work, depending on the house and the budget. We install both and walk you through the tradeoffs before you decide.
- Basement walls: usually closed-cell, thanks to moisture.
Searching for Icynene?
A lot of folks find spray foam by brand name, and Icynene is one we hear often. Here’s the honest truth: the name on the drum matters less than two things. First, is it the right type of foam for your job? Second, does the crew spraying it sweat the details? Ask any contractor those two questions, including us.
Open-Cell vs. Closed-Cell Questions
What’s the real difference between open-cell and closed-cell?
Density. Closed-cell cures hard and dense, packs more R-value per inch, and resists moisture. Open-cell cures soft and light, expands more to fill cavities, quiets sound, and costs less. Both insulate and air seal.
Which foam is better for a crawl space?
Closed-cell. Michigan ground stays damp, and closed-cell acts as a moisture barrier. Open-cell is not a vapor barrier, so it usually isn’t the right tool where moisture is the main concern.
Is Icynene a type of foam?
Icynene is a brand name. What matters more than the brand is whether it’s the right type of foam for your job and whether the crew installing it sweats the details.
We’ll Tell You Which One You Actually Need
Because we install both open-cell and closed-cell, our recommendation isn’t driven by what we sell. It’s driven by your building, your budget, and Michigan’s climate. That’s what an honest quote means to us. No contracts, no pressure, clean job sites, and attention to detail from a crew that takes pride in the work. See all the ways we handle spray foam insulation across Michigan.
Call Vinnie at 989-277-4967 and tell us what you’re working on. We’ll give you a straight answer on which foam fits and what it takes to do the job right.