Premier Insulation Inc - Edmond, OK

Recommended R-Value Insulation

Understanding what insulation level is right for your Oklahoma home

(405) 659-1046

R-value is the single most important number in insulation. It measures how well a material resists heat flow — higher R-value means better insulation, which means lower energy bills, more comfortable rooms, and less wear on your HVAC system. But "how much R-value do I need?" depends on where you live, where in the house you're insulating, and what insulation type you're using. This guide covers the recommended R-values for Oklahoma homes, why we target R-38 for most attic reblows, and what those numbers translate to in real-world inches of fiberglass or spray foam.

What is R-Value?

Insulation is used to restrict the amount of heat that enters or leaves your home. In the summer, insulation blocks outdoor heat from getting in. In the winter, insulation keeps the heat from your furnace from escaping. An R-value is a number that describes insulation's ability to resist heat flow — the higher the R-value, the better it resists heat flow. Doubling the R-value of an insulation material roughly halves the heat loss through it (assuming proper installation, which is a big assumption — see below).

Oklahoma's Climate Zone

Most of Oklahoma, including the entire OKC metro area (Edmond, Norman, Moore, Yukon, Mustang, Guthrie, Choctaw, etc.), sits in U.S. Department of Energy climate zone 3. That zone gets recommendations of R-30 to R-49 for attics, R-13 to R-21 for walls, and R-19 to R-30 for floors over unconditioned spaces. The official DOE max for our zone is R-49 in the attic, but in practice we target R-38 minimum on most reblows — that's the Oklahoma practical standard, what OG&E's HEEP rebate program is built around, and the level where you stop seeing meaningfully better returns per dollar spent.

Recommended R-Values by Area of the Home

Different parts of your home need different insulation levels. Attics matter most because heat rises and most homes have the largest exposed area there. Walls matter less per square foot but cover more total area. Floors over unconditioned spaces (crawlspaces, garages) only matter in winter but make a big comfort difference.

What R-Value Looks Like in Real Inches

R-value depends on both the material and how thick you install it. Blown fiberglass gives you about R-2.9 per inch (so R-38 = ~13 inches, R-49 = ~16 inches). Open-cell spray foam gives about R-3.6 per inch (R-38 = ~10.5 inches). Closed-cell spray foam gives about R-7 per inch (R-38 = ~5.5 inches). That's why spray foam works in shallow cavities where fiberglass would never fit — and why fiberglass is the cost-effective answer when you have plenty of attic depth to work with.

Proper Installation Matters

In order for insulation to achieve its maximum R-value, it must be properly installed. If insulation is not installed correctly, heat will find its way into or out of your home through gaps in coverage, compressed batts, settled blown-in, or air leaks the insulation isn't sealing. A poorly installed R-30 attic can perform like R-15 in real-world conditions. That's why hiring a professional insulation contractor — one who installs to the right depth and density, doesn't compress the material, and addresses air sealing where it matters — pays back over decades of energy bills.

R-Value Doesn't Tell the Whole Story — The Air Infiltration Gap

Here's something most homeowners don't realize: R-value only measures one type of heat loss — conductive heat moving through a still material. It does NOT measure heat lost to AIR LEAKAGE — outside air pulling conditioned air out through gaps, around can lights, through top plates, around plumbing penetrations, and through the soffit-to-attic transition. In a typical Oklahoma home, air infiltration accounts for 25-40% of total heating and cooling loss. R-value can't see any of that. This is why two attics with the same R-value can perform very differently in the real world — and why spray foam at the same R-value as fiberglass typically delivers significantly better comfort and lower bills. Spray foam (both open-cell and closed-cell) expands on contact and seals every crack, gap, and penetration as it cures, eliminating air infiltration as a heat-loss path. Blown fiberglass insulates well against conductive heat transfer but doesn't stop air movement through it. Practical implication: in many homes, R-30 of spray foam delivers roughly twice the real-world performance of R-30 of fiberglass, simply because the foam is doing two jobs (insulating AND air-sealing) while the fiberglass is only doing one. That's why we recommend spray foam for new construction, walls, metal buildings, and any application where air sealing matters as much as insulation value — and why blown fiberglass remains the cost-effective answer for attic floors where the attic is already reasonably well-sealed at the ceiling plane.

Recommended R-Values for Oklahoma Homes

Area of HomeDOE RecommendedOur Default TargetNotes
Attic (most important)R-38 to R-49R-38 minimum on reblowsHighest impact area. R-38 is the practical Oklahoma standard and what OG&E's HEEP rebate program is built around.
Exterior WallsR-13 to R-21R-13 (2x4 walls) or R-19/R-21 (2x6 walls)Determined by the wall framing depth. Modern construction commonly uses 2x6 walls for the extra cavity depth.
Floors Over Unconditioned SpacesR-19 to R-30R-19 to R-25Bonus rooms over garages, floors over crawlspaces. Big comfort impact in winter.
Crawlspace Walls (sealed crawlspace)R-13 to R-19R-13Alternative to insulating the floor above. Works best when the crawlspace is fully sealed.
Cathedral CeilingsR-30 to R-38R-30 (open-cell spray foam in 2x10 rafters)Limited by rafter depth. Spray foam often necessary because batts don't fit thick enough.

Choose the Right Material

Spray Foam vs Fiberglass

Same R-value doesn’t mean same performance — air-infiltration explained.

Open Cell vs Closed Cell

Choosing between spray foam types and the metal-building deep dive.

What Insulation Costs

How target R-value drives Premier’s pricing formula.

Free Insulation Estimates

Call Today

(405) 659-1046

Common Questions

Is R-30 of spray foam the same as R-30 of fiberglass?+
On paper, yes — both deliver R-30 of resistance to conductive heat flow. In the real world, no. R-value only measures conductive heat loss. It doesn't measure air infiltration — outside air leaking through gaps, around penetrations, and through the material itself. In a typical Oklahoma home, air infiltration accounts for 25-40% of total heat loss. Spray foam expands and seals every gap as it cures (acts as both insulation AND air barrier), while fiberglass only resists conductive heat. Practical result: in many homes, R-30 of spray foam delivers roughly twice the real-world performance of R-30 of fiberglass. That's why spray foam is the right call for new construction, walls, metal buildings, and any space where air sealing matters as much as insulation value.
Why do you target R-38 instead of R-49?+
R-38 is the Oklahoma practical sweet spot — it's what OG&E's HEEP rebate program is calibrated around, it's what the energy modeling shows gives the best return per dollar in our climate zone, and the marginal benefit of going from R-38 to R-49 doesn't justify the extra material cost for most homes. We can install higher if you want it, but R-38 is what we recommend by default.
My attic only has R-19 — should I add or remove first?+
Almost always add. We can blow new fiberglass on top of existing R-19 to bring you up to R-38 (or higher). The exception is if the existing material is wet, fire/smoke damaged, pest-contaminated, or badly compressed — in those cases we remove first. We'll tell you which case you're in during the free estimate.
How much money will higher R-value actually save me?+
Going from R-19 to R-38 in an Oklahoma attic typically cuts attic-related heat loss by 50%, which usually shows up as 10-25% reduction in your overall heating + cooling bill. Most homes hit payback in 3-7 years from energy savings alone, often less when you factor in OG&E or Edmond Electric rebates.
Does R-value degrade over time?+
Modern fiberglass and spray foam are designed to maintain their R-value for the life of the building. The exceptions are: insulation that gets wet (loses R-value permanently — has to be removed), insulation that gets compressed (loses R-value while compressed), and insulation that gets pest-contaminated (loses both R-value and your indoor air quality).
Do you offer free estimates?+
Yes — every estimate is free, written, and includes a clear recommendation of what R-value we'd target and why. Call (405) 659-1046 or fill out our contact form to schedule one.

“Love Premier Insulation. I personally wouldn't use anyone else. They are professional, do an excellent job, great at communication letting you know when to expect them and are punctual. They have insulated three homes for me. Great company, excellence, integrity!”

— Lisa Masters, Google Review