Open-Cell vs. Closed-Cell Benefits

The benefits of open-cell spray foam

Open-cell foaming insulation is best suited for interior applications, offering an array of advantages of traditional fibrous insulation materials. Benefits over open-cell foam insulation include:

• Allows for bi-directional drying
• Can accommodate long-term creep and seasonal movement
• Can be installed at a significantly lower cost and target the same specified R-value*
• Is not considered a food source for mold
• Provides sound dampening qualities, ideal for use media or theater rooms
• Lower installed cost, per square foot

The benefits of closed-cell insulation foam

While open-cell foamed insulation has many benefits over traditional insulation types, closed-cell sprayed-in insulation goes beyond to offer additional advantages.  Although closed-cell sprayed insulation foam has a higher per board foot cost, there are benefits that the material offers including:

• Ability to reject bulk water (closed-cell foam insulation is recognized flood resistant material from FEMA.
• Can be applied at very low temperatures (as low as 5°F)
• Adds wall racking strength as well as impact resistance
• Higher R-value* per inch  – easier to accommodate high R-value* requirements in narrow spaces
• Lower vapor permeance (can be a Class II VDR)
• Higher tensile and bond strength

Open-cell is the cheaper version, it’s better at blocking noises, It is a lighter, less dense version, it is more spongy due to the air that gets inside the cells but it is still very effective and better than any option other than closed cell when properly installed for the right application. Open cell expands much more aggressively as soon as it touches the surface or sub straight leaving no crack or crevice unfilled. Open cell can absorb some moisture so avoid applying it where its exposed to cold weather because there is potential for moister in the air to condense on it during the winter months. In this scenario closed cell works better as it is a monolithic vapor and moisture barrier.

Closed cell is a heavier, denser, more solid foam. It’s a more rigid version and it has a higher R value than other types of insulation. It works better at keeping air and water from penetrating the walls as it tends to create a move effective moisture and vapor barrier than open cell. Closed cell is usually the best option all around as long as it is applied correctly, at the right temperature and covers studs to avoid radiant heat from traveling through the studs.

Open cell is between $1.00 and $1.20 a square foot or “Board foot.” Closed cell runs between $1.25 and $1.50 a square foot. Prices vary depending on the space difficulty and other factors like location, prep work, etc. Both Open and Closed cell spray foam work similarly in insulating your structure.