For an Oklahoma City attic, the two foams solve different problems — and the right pick depends on which surface is being sprayed.
For most OKC attic floors, open-cell is the value pick: it expands to fill cavities, seals air leaks, and dampens sound, at a lower cost per board foot. Closed-cell earns its premium in an attic when the roof deck itself is the target, when moisture or condensation is a concern, or when maximum R-value per inch matters because space is tight.
This is a planning guide, not a diagnosis or a quote. A local contractor sizes the actual fix after seeing the attic, roofline, and access.
Softer, expands to fill the cavity, about R-3.5 to R-3.7 per inch. It seals air leaks and insulates in one step, unlike batts that leave gaps around wiring, ducts, and framing. Best for attic floors and interior walls, and where sound control between rooms matters.
Denser, about R-6 to R-7 per inch, and it adds rigidity and moisture resistance. That bond controls moisture and condensation, and the rigidity is a structural plus on rooflines and metal. Best where the roof deck, an exposed wall, or a moisture-prone spot is the job — not just the attic floor.
The full side-by-side comparison, including metal buildings and barndos, is on the open-cell vs. closed-cell page.
Spraying the attic floor keeps the attic itself hot — Oklahoma summers push attics past 130°F — and insulates the rooms below it. Spraying the roof deck brings the attic into the conditioned space, which matters most when ducts run through the attic: long duct runs through a 130°F attic lose cooling before the air ever reaches an upstairs vent. Roof-deck work is where closed-cell's R-value per inch and moisture control most often justify the higher price.
Thin, settled, or pulled-away batts leave bare patches and air paths around can lights, attic hatches, plumbing chases, and top plates. If old batts need to come out first, removal, prep, and access move a real quote up or down regardless of foam type. Note it before asking for a price, so the quote covers the real work.
Steep rooflines, low clearance, and cut-up attic layouts change both the diagnosis and the job. Ventilation and re-entry timing are for the crew to advise on for the specific home — this article does not prescribe them.
Typical attic spray foam jobs in the launch pack run $2,500–$6,000 depending on size and foam type, with open-cell attics at $1,900–$5,250 and closed-cell attics at $2,850–$6,650. Per board foot, open-cell runs about $0.60–$1.30 and closed-cell about $1.30–$2.90. Those are planning ranges only — the only number that counts is the one a local contractor gives after an on-site look. See the full cost guide for what moves a quote.
When the roof deck is the surface, when moisture or condensation is the problem, or when the attic space is so tight that R-value per inch is the deciding factor. In those cases the cheaper foam is not the cheaper job if it does not solve the actual problem.
When the job is a straightforward attic floor over living space, with no moisture problem and room for the thickness open-cell needs. Paying the closed-cell premium there buys R-value and rigidity the attic floor does not need.
Ask which surface is being sprayed, what foam type and thickness are included, and what prep is in the quote — not just the total price. For a typical OKC attic floor, open-cell usually wins on value; for a roof deck or a moisture-prone attic, closed-cell usually wins on performance.
See also: attic work, why upstairs rooms run hot, and the main Oklahoma City spray foam page.