Spray foam is one of the most effective insulation options for homes, businesses, and roofing projects. It expands to seal gaps, improves comfort, and helps reduce energy costs. Choosing between open cell and closed cell depends on your project needs, budget, and environment.
What Is Spray Foam?
Spray foam insulation is created when two chemical components—an isocyanate and a polyol resin—are combined. The mixture expands quickly to fill cracks and cavities, forming an airtight barrier that helps control temperature and moisture inside a structure.
Open Cell Insulation
Open cell insulation is lightweight and expands significantly, making it excellent for filling hard-to-reach areas.
Key benefits include:
- Expands up to 100 times its liquid volume
- Provides strong soundproofing qualities
- More affordable than closed cell alternatives
- Stays flexible after curing, allowing materials to shift naturally
Best suited for:
- Interior walls and ceilings
- Sound reduction between rooms
- Attics and crawl spaces in low-moisture areas
Closed Cell Insulation
Closed cell insulation has a denser structure, offering higher thermal resistance and added strength.
Key benefits include:
- Higher R-value (around R-6 to R-7 per inch)
- Adds rigidity and structural support
- Acts as a vapor barrier when applied at proper thickness
- Resists water absorption, making it useful in flood-prone areas
Best suited for:
- Exterior walls
- Basements and crawl spaces with moisture concerns
- Roof decks or areas needing structural reinforcement
Open Cell vs. Closed Cell: Key Differences
When comparing insulation types, spray foam offers unique benefits whether open or closed cell. The key differences include:
- Density: Open cell is softer and lighter, while closed cell is rigid and compact.
- R-Value: Open cell averages R-3.5 per inch; closed cell ranges R-6 to R-7 per inch.
- Moisture Resistance: Closed cell resists water and vapor; open cell allows controlled permeability.
- Cost: Open cell is budget-friendly; closed cell has a higher upfront cost but superior durability.
Safety and PPE Requirements
Proper personal protective equipment is essential during spray foam installation . Installers should use:
- Full-face respirators or supplied air systems
- Chemical-resistant gloves
- Protective suits with hoods
- Safety goggles during chemical handling
Good ventilation is critical during and after application. Trained professionals should always apply insulation to ensure both safety and long-term performance.
FAQs
Q1: Can open cell insulation be used outdoors?
No. Open cell is moisture-permeable and best suited for interior use. Closed cell is required for exterior walls or damp conditions.
Q2: Does foam insulation need maintenance?
Once installed correctly, it requires no ongoing maintenance. The key is ensuring proper thickness and coverage during application.
Q3: How long does polyurethane insulation last?
It can last the lifetime of a building—often 80 years or more—without sagging, shifting, or losing efficiency.
About Spray Foam Systems
Spray Foam Systems is the #1 spray foam rig builder and spray foam equipment supplier in the United States. Family-owned and proudly serving the industry since 2007, we operate from a 7-acre campus with over 80,000 square feet of dedicated working space in Greensboro, GA. With over 10,000 customers served over the last 18 years, we specialize in delivering high-quality turnkey spray foam systems, distributing top-tier equipment and supplies, and providing nationwide service and training to help contractors grow and succeed in the spray foam insulation and roofing markets.