Spray Foam Attic Insulation: Pros and Cons
Insulating an attic with spray foam is effective but has trade-offs.
Pros
- Excellent air sealing and thermal performance
- Seals gaps that batts can’t reach
- Adds rigidity (closed-cell) and never sags
- Can create a conditioned, usable attic space
Cons
- More expensive than batts or blown-in
- Requires professional installation
- Applied to the roof deck, it can complicate future roof work
Alternatives
If cost is a concern, blown-in cellulose or fiberglass may suit a vented attic. Spray foam shines when you want an unvented, conditioned attic with maximum air sealing.