Open Cell vs Closed Cell Spray Foam Insulation in Lincoln, NE

Quick Comparison: Open Cell vs Closed Cell for Lincoln, NE

Open Cell Spray Foam — Detailed Overview

Open cell spray foam is a soft, low-density foam that expands up to 100 times its liquid volume on application. The foam cells remain open and interconnected, which gives it two key properties: breathability and sound absorption. It's significantly less expensive than closed cell — roughly half the cost per board foot — making it the economical choice for high-volume applications like attics where vapor management isn't the primary concern.

R-value: R-3.5 to R-3.7 per inch. Reaching Nebraska's R-49 attic requirement needs about 13–14 inches of open cell foam, typically applied in two passes.
Best uses in Nebraska: Attic floor insulation (vented attic systems), interior partition walls for sound control, and commercial interior applications.
Never use for: Crawl spaces, basements, rim joists, exterior walls in high-humidity environments, or any below-grade application.

Closed Cell Spray Foam — Detailed Overview

Closed cell spray foam is dense, hard, and has fully enclosed cells that trap a blowing agent — nearly doubling the R-value per inch compared to open cell. At 2 inches of thickness, it forms a Class II vapor retarder, which is the reason it's the required choice for all below-grade and exterior applications in Nebraska's mixed-humid climate.

R-value: R-6 to R-7 per inch. Just 3 inches achieves R-18 to R-21 — meeting Nebraska's R-15 minimum for crawl space walls in half the space fiberglass needs.
Best uses in Nebraska: Crawl spaces, rim joists, basement walls, pole barns, steel buildings, exterior walls, roof decks in conditioned attic systems, and anywhere moisture exposure is a concern.
Additional benefit: Closed cell adds structural rigidity to framing, wall panels, and metal structures — a meaningful bonus in agricultural buildings.

Nebraska-Specific Guidance: What to Use Where

Attics — Use Open Cell

Nebraska attics need to allow moisture to escape through the roof deck in winter to prevent ice dams and condensation within the roof assembly. Open cell foam allows this vapor movement. Exception: if building a conditioned (unvented) attic to house HVAC equipment, closed cell on the roof deck is required. Your contractor will specify which approach is correct for your attic configuration.

Crawl Spaces — Use Closed Cell (Required)

Lancaster County's clay soil retains moisture year-round. Open cell foam in a Nebraska crawl space absorbs this ground moisture, loses thermal performance, and begins harboring mold — we've seen it fail within 5 years. Closed cell foam at 2–3 inches is mandatory for below-grade applications in Nebraska's climate.

Rim Joists — Use Closed Cell (Required)

Rim joists sit at the foundation wall, exposed to exterior temperature and moisture. Closed cell's higher R-value per inch and built-in vapor barrier make it the only correct choice. This is often the highest-ROI spray foam project in older Lincoln homes — stopping drafts immediately and protecting the framing from moisture.

Pole Barns and Steel Buildings — Use Closed Cell

Agricultural and commercial structures need closed cell for moisture resistance, condensation prevention, and structural reinforcement of metal panels. See our dedicated pole barn insulation and steel building insulation pages for details.

Can I Mix Both Types?

Yes — and for most Lincoln homeowners doing a full home insulation upgrade, the hybrid approach is the right answer. Use closed cell in the crawl space and rim joists where moisture management is critical, and open cell in the attic where breathability and cost savings matter. This approach maximizes performance where it counts and keeps your total project cost reasonable. The most common Lincoln project we see is exactly this combination: closed cell crawl space + open cell attic, typically $5,000–$10,000 all-in.

Nebraska Energy Rebates — Which Foam Qualifies?

Both open cell and closed cell spray foam can qualify for Lincoln Electric System (LES) and OPPD energy efficiency rebates when used in qualifying applications. The key is meeting minimum R-value thresholds specified by each utility's program. Contact LES or OPPD before your project to confirm current rebate availability — programs change annually. The federal 25C energy efficiency tax credit may also apply regardless of foam type when installed in an existing home.

Frequently Asked Questions

Also see: Spray foam insulation cost in Lincoln | Attic spray foam insulation | Crawl space insulation