How Much Does Spray Foam Insulation Cost? Complete 2025 Guide

Spray foam insulation is having a moment, and for good reason. In 2025, more homeowners, farmers, and business owners are choosing it for its unbeatable air sealing, high R-value, and energy-saving potential. But the big question remains: How much does spray foam insulation cost, and is it worth it?



In this detailed guide, we’ll break down real-world pricing data, cost factors, Colorado-specific building code requirements, and long-term value insights. We’ll also answer some of the most common FAQs and wrap up with how Mile High Centennial Insulation can help you get it done right the first time.

What Is Spray Foam Insulation?

Spray foam insulation is a two-part liquid polyurethane mixture that expands into a dense foam when applied. The foam fills cracks, gaps, and cavities, creating both an air barrier and an insulating layer.

There are two main types:

Open-cell spray foam

• Light and spongy texture
• Lower cost
• R-value: ~R-3.5 to R-4 per inch
• Good for interior walls, soundproofing, and budget-friendly insulation
  

Closed-cell spray foam

• Dense and rigid structure
• Higher cost but much higher R-value (~R-6 to R-6.5 per inch)
• Excellent moisture resistance
• Often used for exterior walls, basements, crawl spaces, and roofs
  

U.S. Department of Energy (DOE) research shows that spray foam can reduce air infiltration by up to 40% more than traditional insulation. This means a warmer winter, a cooler summer, and lower energy bills all year round.

Average Spray Foam Insulation Costs in 2025

The cost of spray foam insulation varies depending on type, thickness, labor rates, and location. Here’s a comprehensive cost breakdown using data from sources like HomeAdvisor, Angi, RSMeans, and industry pricing averages:

Tip: In Centennial, CO, costs may be slightly higher than national averages due to labor rates and climate zone requirements.

What Affects the Cost of Spray Foam Insulation?

When you request quotes, you might notice big variations. That’s because spray foam pricing isn’t one-size-fits-all. The main cost drivers include:

• Type of foam used – Closed-cell foam costs more but delivers higher R-values and acts as a vapor barrier.
• Project size and accessibility – A wide-open new construction attic is faster (and cheaper) to insulate than a cramped retrofit crawl space.
• Desired R-value – Higher insulation levels require more foam and labor.
• Location and climate zone – Centennial is in IECC Climate Zone 5B, which has stricter insulation requirements than warmer regions.
• Preparation work – Removing old insulation, sealing leaks, or addressing mold/moisture issues can increase costs.
  

Costs by Area of Application

The location you insulate makes a big difference in the final price.

Attic Insulation

Attics often need the most insulation due to rising heat loss. Spray foam here runs $1,700 to $5,075, depending on foam type and thickness. In cold climates like Colorado’s, closed-cell foam may be worth the extra cost for its higher R-value and moisture resistance.

Wall Insulation

For new construction, wall insulation is straightforward and usually costs less per square foot than retrofits. Expect $1.25 to $4.50 per sq. ft.

Basement & Crawl Space Insulation

These spaces benefit from spray foam’s ability to block moisture and prevent mold. Pricing averages $1,070 to $6,170 depending on the square footage and type of foam.

Garage Insulation

Insulating a 20×20 ft garage (about 400 sq. ft.) costs between $1,400 and $4,000, depending on foam type and whether you’re doing just the walls or adding the ceiling.

Building Codes & Compliance in Centennial, CO

Centennial falls under IECC Climate Zone 5B. Here’s what that means for spray foam insulation:

• Attics – Minimum R-49 (roughly 15 inches of open-cell foam or 8 inches of closed-cell foam).
• Walls – Minimum R-20 cavity or R-13 + R-5 continuous insulation.
• Crawl spaces – Minimum R-19 floor insulation or R-15 walls.
• Fire Safety (IRC Section R316) – Spray foam must be covered with a 15-minute thermal barrier (e.g., drywall) when inside living spaces.
• Vapor barriers – Required on the warm side of insulation in certain moisture-prone areas.

Following these codes is crucial not only for energy savings but also for passing inspections and maintaining property value.

Long-Term Savings & ROI

While spray foam costs more upfront, the DOE estimates it can reduce heating and cooling costs by up to 20–40% annually. For many Centennial homeowners, that means the investment can pay for itself in 3–6 years through utility savings alone.

It also lasts 20+ years without sagging, shifting, or settling, unlike fiberglass, which can degrade over time.

DIY vs. Professional Installation

DIY spray foam kits cost less upfront, around $300 to $2,000, but come with risks:

• Uneven application
• Missed air leaks
• Poor adhesion or curing in cold weather
• Lack of code compliance

Professional installers like Mile High Centennial Insulation bring proper equipment, training, and experience to ensure your project meets local codes and delivers the promised R-value.

Common Myths About Spray Foam

Myth: Spray foam is too expensive compared to fiberglass.

Reality: While fiberglass is cheaper upfront, spray foam’s tighter seal often leads to higher energy savings and fewer drafts, lowering lifetime costs.

Myth: You can’t use spray foam in older homes.

Reality: Professional installers can retrofit spray foam into existing walls, attics, and crawl spaces without major demolition.

Real-World Example: 20×20 Garage in Centennial, CO

Let’s say you want to insulate a two-car garage (400 sq. ft.) in Centennial:

• Open-cell foam, walls only: ~$1,400 – $2,800
• Closed-cell foam, walls only: ~$2,000 – $4,000
• Walls + ceiling: Add $1,000–$1,500 to the above numbers

Total project: $2,000 to $5,500, depending on foam type and coverage area.

Why Choose Mile High Centennial Insulation?

When it comes to spray foam, experience matters. Mile High Centennial Insulation offers:

• Residential, agricultural, garage, attic, and commercial insulation expertise
• Knowledge of Colorado building codes and climate-specific needs
• Licensed, insured, and trained technicians
• Long-lasting, high-performance insulation tailored to your property

Contact Information:

(720) 637-4759

contact@insulationcentennial.com

6707 S Vine St, Centennial, CO 80122, USA

Ready to make your home or business more comfortable and energy efficient? Get a free on-site estimate today from Mile High Centennial Insulation.

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