Attic Insulation 2026 — Blown-In vs Batts vs Spray Foam Comparison

Published 2026-04-25 · Updated 2026-04-25 · 6 min read · By Zomg The Handyman
TL;DR

Three types of attic insulation. Blown-in is easiest retrofit. Batts are cheapest. Spray foam is best but most expensive.

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Most California homes built before 2008 have under-insulated attics. Three retrofit options. The right choice depends on your budget and access.

Quick Comparison

PickBest ForApprox Price
Blown-InOwens Corning AttiCat Expanding Attic Insulation$30-$50 / bag

Our Picks

Blown-In
Recommended on Amazon
Owens Corning AttiCat Expanding Attic Insulation
Blown-in attic insulation. R-30 in a single 8-bag layer.
$30-$50 / bag View on Amazon →

Blown-In Cellulose

Best for retrofits with limited access. Settles around obstacles. Achievable R-value: R-30 to R-49.

Fiberglass Batts

Cheapest. Works for new construction or open-access attics. R-value depends on thickness.

Spray Foam

Best R-value per inch. Air sealing built-in. Most expensive. Pro install required.

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Frequently Asked Questions

Cheapest option?

Fiberglass batts (~$1.50/sqft material).

Best for retrofits?

Blown-in cellulose. Owens Corning AttiCat is the consumer DIY brand.

Spray foam worth it?

For high-end energy efficiency, yes. Cost-prohibitive for most retrofits.

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