You’re building and planning out your grow room and know you want spray foam insulation, but do you go with open cell or closed cell?

The Internet isn’t a great help here, as there are a lot of misconceptions about foam insulation floating around the World Wide Web. While you’re likely reading this online, I promise we won’t steer you in the wrong direction.

RetroFoam of Michigan has been installing foam insulation in homes, pole barns, and businesses since 2002, and now we can say we’ve also insulated our fair share of grow rooms.

We are on a mission to educate everyone who is considering foam insulation for their project. With that, we will provide you with the pros and cons of open cell and closed cell spray foam so you can choose the best insulation for your grow room.

Grow Room Spray Foam Insulation: Open Cell vs Closed Cell

You might be thinking that one spray foam insulation will outperform the other, but when it comes down to open cell and closed cell that’s not the case.

It’s more about which product better fits your needs, and your grow room. Now, let’s dig into these pros and cons.

Open Cell Spray Foam Pros:

Open cell spray foam is a lightweight material that really expands, meaning it can squeeze into all those hard-to-reach spots when it's installed.

Plus, it uses water as a blowing agent, making it a more eco-friendly choice.

One of the big perks of open cell spray foam is its sound dampening abilities. So, if you're working in your grow room, you don't have to worry about noise leaking out and bothering anyone nearby. On top of that, it creates an airtight seal that helps control temperature and humidity -- super important for maintaining the right environment in your grow space.

And just like closed cell foam, open cell also helps keep those strong odors, like marijuana, from spreading out of the room.

Open Cell Spray Foam Cons:

If the walls in your grow room are left uncovered, open cell spray foam could get damaged if something bumps into it.

Open cell is also moisture permeable, meaning water can pass through it, and some brands out there can even hold onto that moisture.

Closed Cell Spray Foam Pros:

Closed cell spray foam is a much denser material, making it a solid choice for grow rooms with exposed walls.

Thanks to its density, water can't move through closed cell spray foam, giving you some extra peace of mind when it comes to moisture.

Like open cell, closed cell spray foam creates an air seal, helping you keep the perfect environment for growing marijuana. On top of that, both types of spray foam aren't a food source for pests, and the air seal they create makes it tough for critters to sneak into your grow room -- they just can't find a way in.

Another bonus of closed cell spray foam -- it comes with a built-in vapor barrier, giving you extra protection against moisture.

Closed Cell Spray Foam Cons:

Closed cell spray foam comes with a higher price tag than open cell, so it's something to keep in mind.

One thing to watch out for is if there's a water leak in your grow room -- closed cell spray foam can actually hide the leak since water can't pass through it.

Also, since closed cell is a heavier material, it might not be the best option for an exposed ceiling in your grow room. You'll want to consider whether it's the right fit for your space before deciding.

Choosing the Best Spray Foam for Your Grow Room

When it comes down to it, both open cell and closed cell spray foam offer some great benefits for your grow room.

Making the decision of which to go with really comes down to what will work best for your individual needs and project. If you want to learn even more about spray foam insulation, the Learning Center on our website is a great place chock-full of information.

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