Blown-In vs. Spray Foam Insulation: Which Is Right for Your Home?

When it comes to improving home comfort and cutting energy bills, **insulation is one of the smartest upgrades you can make**. But not all insulation types are the same—and two of the most popular options today are blown-in insulation and spray foam insulation.

In this guide, the experts at The Cozy Penguin Insulation Company break down the differences between these two materials so you can make an informed decision for your home in Central Pennsylvania.

At a Glance: Key Differences

Feature	Blown-In Insulation	Spray Foam Insulation
Best Use	Attics, walls, retrofits	Crawl spaces, rim joists, tight gaps
R-Value	Moderate (R-2.2 to R-3.8 per inch)	High (R-3.5 to R-7 per inch)
Air Sealing	Minimal	Excellent
Moisture Barrier	No	Yes (closed-cell only)
Cost	Lower	Higher

What Is Blown-In Insulation?

Blown-in insulation consists of loose fiberglass or cellulose fibers that are blown into attics or wall cavities using a specialized machine. It’s ideal for adding insulation to existing homes with minimal disruption.

Best used for: Attic floors, retrofit wall insulation, hard-to-reach cavities

Quick and affordable installation
Good for filling gaps and irregular areas
Often made from recycled materials (eco-friendly)
Improves thermal performance in under-insulated homes

💡 Great choice for homes in Harrisburg and Lancaster with older attics or limited budget.

What is the Best Insulation for Homes in Central Pennsylvania?

What Is Spray Foam Insulation?

Spray foam insulation is a liquid polyurethane that expands into a rigid foam when applied, forming an airtight, moisture-resistant barrier. It’s highly effective at sealing cracks and improving insulation in tight or complex areas.

Best used for: Crawl spaces, rim joists, basements, and irregular surfaces

Highest R-value per inch (especially closed-cell)
Excellent air sealing and draft control
Helps deter moisture, mold, and pests
Long-lasting with minimal maintenance

🔒 Ideal for Central PA homes with cold floors, moisture-prone basements, or significant air leakage.

Learn about Removing Old Insulation

Which Insulation Is Best for Your Home?

Choosing between blown-in and spray foam insulation depends on several factors:

Your home’s age and construction
Current insulation levels
Moisture concerns
Budget and long-term goals

Blown-in insulation is a cost-effective way to top off attic insulation or fill existing walls quickly. Spray foam insulation is ideal when you need a tight seal, high R-values, or moisture protection—especially in basements or crawl spaces.

Q: Is spray foam insulation worth the extra cost?

A: Yes—especially in areas with air leaks or moisture issues. It provides long-term savings through improved energy efficiency and durability.

Q: Can I use both blown-in and spray foam insulation?

A: Absolutely. Many homes benefit from a hybrid approach. For example, spray foam in the crawl space and blown-in in the attic.