Open‑Cell vs Closed‑Cell Foam: What’s Right for Residential vs Commercial Use?
When it comes to insulation, spray foam is one of the most energy-efficient and versatile options on the market. But not all spray foam is created equal. The two main types—open-cell and closed-cell—serve different purposes depending on the structure, climate, and specific performance goals. So, which is right for your residential or commercial project?
Let’s break it down.
Understanding the Basics
Open-Cell Spray Foam
This type of foam is light, soft, and flexible. The cells in the foam aren’t completely closed, which allows air to fill in the gaps, making it less dense and more breathable.
Closed-Cell Spray Foam
Much denser and more rigid, closed-cell foam features completely sealed cells filled with a gas that helps the foam expand and insulate more effectively. It offers a high R-value and acts as a vapor barrier.
R‑Value: Insulating Power
Open-Cell R-Value: \~3.5–3.9 per inch
Closed-Cell R-Value: \~6.0–7.0 per inch
Which wins?
Closed-cell foam offers nearly double the insulation power per inch. It’s ideal for spaces where you want maximum energy efficiency with minimal thickness—like metal buildings or narrow wall cavities.
Open-cell, on the other hand, is still very effective for most residential applications, especially in moderate climates.
Moisture Resistance
Open-Cell: Vapor-permeable; allows moisture to pass through. Not suitable for areas prone to water exposure without additional vapor barriers.
Closed-Cell: Acts as a vapor barrier and is waterproof. Ideal for crawl spaces, basements, and commercial structures.
Which wins?
Closed-cell foam is the clear winner in terms of moisture resistance, making it better suited for foundations, roofs, and areas prone to water intrusion.
Soundproofing Abilities
Open-Cell: Excellent sound dampening due to its soft, air-filled structure.
Closed-Cell: Less effective at absorbing sound; its density reflects sound waves rather than absorbing them.
Which wins?
Open-cell foam is the ideal choice for interior walls in homes or offices where sound control is a top priority, such as home theaters, bedrooms, or conference rooms.
Structural Support
Open-Cell: Flexible and not load-bearing. It may shrink slightly over time.
Closed-Cell: Adds structural integrity to walls, ceilings, and roofs. It can strengthen sheathing and resist impact.
Which wins?
Closed-cell foam not only insulates but also reinforces. It's a top choice for commercial buildings, pole barns, and areas requiring durability.
Residential vs Commercial: What's Best?
Residential Use
Open-cell foam is perfect for most attics, wall cavities, and living spaces.
It’s cost-effective, provides excellent soundproofing, and expands well to seal cracks and gaps.
Use closed-cell foam in basements, crawl spaces, or homes in flood-prone areas for added protection and insulation.
Commercial Use
Closed-cell foam is typically preferred for its high R-value, moisture resistance, and strength.
Ideal for warehouses, steel buildings, and other structures that require both insulation and durability.
Some commercial interiors may still benefit from open-cell for acoustic control in offices or studios.
Final Thoughts
Choosing between open-cell and closed-cell spray foam depends on your goals, climate, and building type. While both offer excellent insulation, knowing where and how to use each type ensures you get the best performance, comfort, and energy savings.
Need help deciding what’s right for your project?
Our team at Canaan Companies specializes in spray foam solutions for residential and commercial buildings. Contact us today for a free consultation—we’ll help you insulate smarter.