What Is Open Cell Spray Foam?
Open cell spray foam is a soft, flexible insulation material made up of tiny cells that are intentionally left open during the curing process. This gives the foam its signature spongy texture and allows it to expand dramatically — up to 100 times its original volume —
filling every gap, crack, and cavity in your walls, attic, or crawl space completely. The result is a seamless air barrier that traditional fiberglass insulation simply cannot replicate.
Benefits of Open Cell Spray Foam
Superior Air Sealing
Open cell foam expands aggressively to fill every void, creating a continuous air barrier that eliminates drafts and reduces conditioned air loss. This is something fiberglass batts can never fully achieve, no matter how carefully they're installed.
Budget Friendly
Open cell foam costs less per square foot than closed cell, making it an excellent option for larger areas like attic rooflines where covering a lot of surface area is the priority. You get a high-performing, long-lasting insulation product at a more accessible price point.
Flexible and Wood-Friendly
Pennsylvania's four-season climate means your home's wood framing expands and contracts constantly with changes in temperature and humidity. Open cell foam moves with the wood, so it won't crack, pull away, or leave gaps over time the way rigid insulation can.
Excellent Soundproofing
One of the biggest advantages of open cell foam over other insulation types is its sound dampening ability. Its open, porous structure absorbs sound waves rather than reflecting them — making it a popular choice for interior walls between rooms, home offices, bedrooms, and any space where noise control matters.
Long Lasting
Unlike fiberglass batts that sag, settle, and lose R-value over time, open cell spray foam maintains its performance for the life of your home — no replacement, no topping off, no maintenance.
Where Is Open Cell Spray Foam Used?
Open cell foam is best suited for interior applications where moisture exposure is limited. Common uses we see throughout our Lancaster, Chester, and York County service area include:
Attic rooflines — Creates a conditioned attic space that dramatically reduces heat gain in summer and heat loss in winter
Interior walls — Soundproofing between bedrooms, living spaces, and home offices
Basement rim joists — Seals one of the most common air leak points in Pennsylvania homes
Crawl spaces — Improves comfort and reduces energy loss in unconditioned spaces
New construction — An increasingly popular choice among builders throughout southeastern PA for its performance and value
Open Cell vs. Closed Cell — Which Do I Need?
This is the most common question we get, and the honest answer is: it depends on your project. Open cell foam is a great fit for interior applications, soundproofing, and budget-conscious projects. Closed cell foam is the better choice when moisture resistance, higher R-value per inch, or structural reinforcement is required — like exterior walls, below-grade applications, or areas exposed to high humidity.
Not sure which is right for your home? Give us a call and we'll walk you through it. We'll never recommend a product that's more than what your project actually needs.
Frequently Asked Questions
Is open cell spray foam a good insulator?
Yes. Open cell foam has an R-value of approximately R-3.5 to R-4 per inch. While lower than closed cell, it still significantly outperforms fiberglass in real-world conditions because of its complete air sealing ability. Air leakage accounts for a large portion of home energy loss — and open cell stops it cold.
Can open cell spray foam get wet?
Open cell foam is not a moisture barrier and should not be used in areas with direct water exposure. If your project involves a damp basement, crawl space walls, or exterior applications, closed cell foam is the better choice. We'll help you determine the right product for your specific situation.
Is open cell foam safe once it cures?
Yes. Once fully cured — typically within 24 hours — open cell spray foam is inert and safe. During installation, the area needs to be vacated and properly ventilated, but after curing there are no ongoing off-gassing concerns.
How long does open cell spray foam last?
Properly installed open cell foam can last the lifetime of your home — 50 years or more. It doesn't settle, compress, or lose R-value the way fiberglass does, making it a one-time investment that keeps performing year after year.
How much does open cell spray foam cost?
Cost varies based on the size of the area, thickness required, and accessibility of the space. We offer free, no-obligation estimates for all projects throughout our service area. Call or text us at 717-990-8301 and we'll get you a straight, honest number.
Serving Morgantown, PA and the Surrounding Area
Sunrise Valley Spray Foam is a locally owned and operated business serving homeowners and contractors throughout Lancaster County, Chester County, York County, Berks County, and the greater southeastern Pennsylvania area. The owner is on every job — so you always get experienced hands and direct accountability from start to finish.