Open Cell vs Closed Cell Foam Insulation: Which is Better for My Home?
You already know foam insulation doesn’t just block heat flow, but it also stops air flow keeping your home more comfortable while reducing your energy bills.
While open cell and closed cell are both spray foam insulations, there are differences between the two as far as how they are applied, their efficiency in homes compared to other structures, and how they work in general.
RetroFoam of Michigan has been insulating homes and pole barns across the lower peninsula for more than 15 years. As foam insulation is our specialty, we know quite a bit about what type of spray foam will work best in what areas.
Open Cell vs Closed Cell Foam Insulation
Let’s walk through the two and figure out which is better for you and your application.
Open Cell and Closed Cell Spray Foam Composition
Open cell foam is lightweight, pliable and easy to work with, whereas closed cell foam is rigid and very dense.
For example, if you needed to run new wiring, open cell spray foam is going to be much easier to work with because it is so pliable.
On the other hand in pole barns, closed cell’s rigid structure and durability makes it ideal for exposed walls because it won’t be damaged if it is bumped by machinery or tools.
How Much Do Open Cell and Closed Cell Spray Foam Expand?
Open cell spray foam has a very high expansion rate, sometimes as much as 100 times over. This makes it an ideal option for homes because it gets in the nooks and crannies in attics, crawl spaces, and rim joists.
Closed cell spray foam has very minimal expansion when applied.
What are the Blowing Agents for Open Cell and Closed Cell Spray Foams?
A safety feature with open cell spray foam is it typically uses water as its blowing agent.
Closed cell spray foam uses a chemical agent that can give off a temporary odor with some brands.
What is the Moisture Permeability of Open Cell and Closed Cell Spray Foams?
Open cell foam is inherently moisture permeable, depending on the brand there are differences whether or not free standing water can be absorbed.
For example, Icynene spray foam only retains up to 5 percent of its weight in water. Other open cell spray foam brands can retain as much as 75 percent of its weight in water.
Closed cell spray foam on the other hand is 100 percent moisture impermeable. While the moisture impermeable option might sound better, one scenario where open cell can be beneficial is on a roof deck of an attic. If a leak were to occur the foam would be discolored and let you know immediately where the leak was happening so it could be quickly repaired.
Closed cell spray foam will conceal the leak until the water builds up somewhere else and cause much bigger problems.
What are the Sound Dampening qualities for Open Cell and Closed Cell Spray Foams?
The thicker, softer material of open cell reduces sound waves much better than the tight, dense closed cell.
Does Open Cell and Closed Cell Spray Foams Create an Air Seal?
Both open cell and closed cell spray foams provide an air seal which is going to help eliminate drafts, heat loss, and moisture from getting into your home.
That air seal can only be achieved with a minimum recommended thickness of 2 inches of closed cell and 3 inches of open cell.
What is the R-Value for Open Cell and Closed Cell Spray Foam?
Closed cell spray foam, being more dense than open cell spray foam, will have a higher R-value per inch. However, when you apply a typical depth of open cell -- 3 inches -- and closed cell -- 2 inches -- you are stopping approximately the same amount of heat flow.
How Much Does Open Cell and Closed Cell Spray Foam Cost?
Installation of open cell spray foam is much easier and the foam itself is less expensive to produce.
Closed cell spray foam, besides being more expensive to make, must be applied in thinner coats, often requiring several passes which can drive up installation time and cost.
Which Spray Foam Insulation Meets Your Needs?
Spray foam insulation, regardless of what type, is going to create an air seal and insulate your home. Like most things, it’s not as easy as picking one over the other, it’s about what’s right for your home.
Balancing the pros and cons of each type of spray foam insulation isn’t hard if you’ve got all the information in front of you. Hopefully this article has helped you with that and with deciding which spray foam is best for you.
When you are ready to schedule a free estimate and live in Michigan’s lower peninsula, give us a call at 866-900-3626 for a free estimate, or fill out the form on our website.