Three ways to insulate, three different jobs. The honest comparison — including where the cheaper options genuinely win.
Spray foam wins on air sealing and R-value per inch — it is the only one of the three that stops air movement while it insulates, and that is where most of the comfort and bill difference lives. Blown-in and fiberglass win on upfront cost, often by a wide margin, and for a straightforward attic they can be the right buy. The correct choice depends on the job: a leaky attic with ducts in it is a foam job; a simple vented attic that just needs more depth is usually a blown-in job. Anyone who tells you one material wins everywhere is selling that material.
This page compares the three the way an Oklahoma City homeowner actually has to decide between them: what each does about air leaks, what each delivers per inch, what each typically costs installed, and how each behaves over the years you will own the house. Foam pricing uses the same Oklahoma City ranges as our spray foam cost guide; blown-in and batt figures are published national ranges. All figures are typical planning ranges, not quotes.
| Spray foam | Blown-in (fiberglass / cellulose) | Fiberglass batts | |
|---|---|---|---|
| Air sealing | Insulates and air-seals in one pass — expands into gaps, cracks, and penetrations and bonds in place | None on its own; loose fill slows air slightly but leaks pass through it. Needs separate air-sealing work first | None; batts are cut and friction-fit, so gaps around wiring, pipes, and framing are the norm |
| R-value per inch | About R-3.7 (open-cell) to R-6.5 (closed-cell) | About R-2.2–3.8 depending on material | About R-3.1–3.8 |
| Installed cost (typical) | About $1.50–$4.50 per sq ft in the OKC area; contractors quote $0.60–$1.30 per board foot for open-cell and $1.30–$2.90 for closed-cell | About $1.00–$2.50 per sq ft installed (national ranges); a typical attic job runs roughly $1,000–$2,500 — the budget option | About $0.80–$2.60 per sq ft installed (national ranges); the cheapest way into open, regular framing |
| Lifespan & settling | Does not settle, sag, or shift once cured; expected to perform for the life of the building | Settles — cellulose commonly 15–20% of installed depth, blown fiberglass a few percent — losing R-value unless extra depth was blown in; can be topped up | Sags and pulls away from framing as it ages; compression around obstructions quietly erases R-value |
| Moisture behavior | Closed-cell resists water absorption and acts as a vapor retarder; open-cell lets vapor pass but blocks the air movement that carries most moisture | Absorbs and holds moisture; wet cellulose slumps and loses R-value, wet fiberglass mats down. Neither stops the humid-air leaks behind most moisture problems | Loses insulating value when wet and dries slowly; does nothing to stop air-driven moisture |
| Sound | Open-cell is an excellent sound dampener — a real reason it is chosen for interior walls and media rooms | Good sound absorption in walls and between floors; cellulose is notably dense and quiet | Moderate; standard batts help, dedicated acoustic batts help more |
| Best uses | Roofline (sealed attic) insulation, leaky attics, crawl spaces, rim joists, metal buildings and barndominiums, anywhere depth is limited or air leaks are the problem | Attic floor top-ups in vented attics, adding depth over existing insulation, budget retrofits after air sealing | New construction and open stud walls, simple rectangular cavities, DIY-friendly projects |
Two rows decide most real-world jobs. The first is air sealing: insulation ratings assume still air, and neither batts nor loose fill stop air from moving through them — which is why a leaky R-49 attic can underperform a sealed R-38 one every Oklahoma summer. The second is cost per job, not per inch: blown-in reaches R-38 in an open attic for a fraction of foam's price, and pretending otherwise helps nobody. Read both rows together and the right answer for your house usually picks itself.
We sell foam referrals, so weigh this accordingly — but these are the jobs where we would tell a neighbor to buy the cheaper material:
The condition attached to every item above: air seal first. Caulk and foam the penetrations, seal the top plates and the attic hatch, then add the cheap depth. Blown-in over an unsealed attic floor is money spent insulating a sieve.
Foam's premium buys one thing the others cannot provide at any thickness: a continuous air barrier bonded to the surface. That single property is what makes these jobs foam jobs:
Which foam, once you are in foam territory, is its own decision — R-value per inch, moisture behavior, and price per board foot all differ. Start with open-cell vs. closed-cell, then price the job with the Oklahoma City cost guide.
Yes, and the hybrid is often the smartest dollar in the whole comparison. Flash-and-batt sprays a thin layer of closed-cell foam — the "flash," typically 1–2 inches — directly against the roof deck or exterior wall to do the air-sealing and moisture work, then fits a fiberglass batt behind it for bulk R-value at batt prices. The same logic works in attics, where foam seals the roofline and blown-in adds cheap depth on the floor. What a hybrid cannot do is cheat the foam layer too thin: the flash coat has to be thick enough for our climate zone to keep the assembly's moisture behavior safe, which is why the design — foam type, flash thickness, finished R-value — should be in the written quote, not a handshake.
Call (405) 874-6813 for a free quote — foam, hybrid, or an honest "blown-in is all you need."
It depends on the job. Fiberglass and blown-in insulation cost far less up front and are a sensible buy for a simple vented attic on a budget. Spray foam earns its premium where air movement is the real problem — leaky attics, ducts in the attic, hot upstairs rooms, crawl spaces, and metal buildings — because it insulates and air-seals in the same pass, which fiberglass and blown-in cannot do at any thickness. The honest test is not which material is "best" but which problem you are paying to solve.
Published estimates commonly put spray foam's payback period at about 3 to 7 years, with energy-bill savings claims across sources ranging from 10% to 50% — a spread wide enough that you should distrust any guaranteed percentage. Payback is fastest in leaky, under-insulated homes, where air sealing does work blown-in and batts cannot, and slowest in tight, newer homes. Many Oklahoma City homeowners also count the comfort — an upstairs that finally matches the downstairs — as part of the return.
Yes — hybrid systems are common and legitimate. The best known is flash-and-batt: a thin layer of closed-cell spray foam (the "flash") sprayed against the roof deck or wall to air-seal and control moisture, then a fiberglass batt (the "batt") fitted behind it for cheaper bulk R-value. The same idea works in attics, where foam seals the roofline and blown-in adds depth on the floor. Done in the right order and thickness for the climate zone, a hybrid can capture most of foam's air-sealing benefit at meaningfully less than a full-foam job — ask for the design in writing so the foam layer is thick enough to do its job.
Yes. Blown-in fiberglass and cellulose both settle after installation — cellulose commonly settles around 15–20% of its installed depth, and blown fiberglass settles a few percent — which lowers the effective R-value unless extra depth was blown in to compensate. Settling is gradual and the fix is simple: a top-up pass restores the depth. Spray foam, by contrast, is bonded in place and does not settle, sag, or shift once cured.
For a simple vented attic with no ducts or equipment in it, blown-in over a properly air-sealed attic floor is the value pick. For a leaky attic, ducts or an air handler in the attic, or a home with hot upstairs rooms, spray foam — on the attic floor or the roof deck — solves the air-movement problem that extra depth of blown-in cannot. Oklahoma City attics target R-38 (IECC Climate Zone 3); whichever material you choose, air sealing matters as much as hitting the number.