Walk into any insulation discussion and you'll hear terms like R-value, open-cell, cellulose, mineral wool, and rigid board. Here's a plain-English guide to the main insulation types and where each one shines.
Spray Foam
What it is: A two-part liquid that expands into solid foam on contact. Available in open-cell (lighter, flexible, R-3.7/inch) and closed-cell (dense, rigid, R-6.5/inch).
Best for: Crawl spaces, rim joists, roof decks, and anywhere air sealing is critical. The only insulation that seals and insulates simultaneously.
Blown-In (Loose-Fill)
What it is: Cellulose (recycled paper) or fiberglass blown in with specialized equipment. Cellulose: R-3.5/inch. Fiberglass: R-2.5/inch.
Best for: Attics (top-up over existing insulation), enclosed wall cavities (dense-pack), and any area where seamless coverage matters.
Batts & Rolls
What it is: Pre-cut panels of fiberglass (R-3.2/inch) or mineral wool (R-3.8/inch) designed to fit between standard framing.
Best for: New construction walls, floors, and ceilings. Mineral wool is excellent for fire resistance and sound dampening.
Rigid Board
What it is: Solid panels of XPS, EPS, or polyiso foam. R-values range from R-3.8 to R-6.5 per inch depending on type.
Best for: Foundation walls, exterior continuous insulation, and crawl space walls. Provides insulation and moisture resistance.
Which Should You Choose?
Most homes benefit from a combination. A common high-performance approach: spray foam on rim joists and crawl space, blown-in cellulose in the attic, and batts in wall cavities. The right mix depends on your home's construction, climate zone, and budget.
Contact us for a recommendation tailored to your home.