How much does spray foam insulation cost in South Carolina?

Spray foam insulation in South Carolina typically costs $1.00–$1.60 per board foot for open-cell foam and $1.60–$2.60 per board foot for closed-cell foam. Attic and crawl-space scopes are quoted from measured board feet after an on-site evaluation. Final pricing depends on access, required thickness, and any removal of existing insulation.

What is the difference between open-cell and closed-cell spray foam for South Carolina homes?

Closed-cell spray foam delivers approximately R-6 to R-7 per inch; open-cell approximately R-3.5 to R-4 per inch. Closed-cell is recommended for South Carolina crawl spaces and moisture-prone areas because it provides a Class II vapor retarder — critical in a hot, humid climate. Open-cell is preferred for many attic applications and costs less per board foot. Our service area sits in IECC Climate Zone 3A); code requires R-38 (Zone 3A min) for attics. Code requires R-38 (Zone 3A min).

How long does spray foam insulation last in a South Carolina home?

Spray foam is a permanent insulation with an expected lifespan of 80+ years without sagging or compressing when properly installed. Unlike fiberglass batts, it does not compress, sag, or absorb moisture. In South Carolina's hot, humid climate, closed-cell foam also resists the moisture infiltration that shortens the life of other insulation types.

How much can spray foam insulation reduce energy bills in South Carolina?

Homeowners typically see 20–40% lower heating and cooling costs after air sealing and insulation, depending on the home's starting condition. In South Carolina's cooling-dominated climate, spray foam's dual function as insulation and air barrier stops the humid-air infiltration and radiant heat that fiberglass batts alone cannot address.

Are rebates or tax credits available for spray foam insulation in South Carolina?

Duke Energy and local programs offer rebates for qualifying insulation and air-sealing upgrades; amounts vary by measure and change annually — confirm current amounts before your estimate. The federal 25C Energy Efficient Home Improvement Credit ended December 31, 2025. No federal tax credit currently applies to insulation work; utility rebates remain available.

How Spray Foam Lowers Your Duke Energy Bill in the Upstate

We’re South Carolina Spray Foam Insulation, a family-owned company, and we’ve spent more than 15 years insulating homes and commercial buildings across Greenville and the rest of the Upstate. The question behind most of our estimates isn’t really about R-value. It’s about the Duke Energy bill — why it climbs every July and January, and whether spray foam will actually bring it down. The short answer is yes, and the longer answer is worth understanding before you spend a dollar.

Where Your Energy Is Actually Lost

Heating and cooling is the largest energy load in most Upstate homes, and the conditioned air your system works to produce escapes through the same three places in house after house.

The crawl space. Most homes from Greenville through Anderson and Spartanburg were built with vented crawl spaces, and much of the ductwork runs through them. A damp, leaky crawl space lets ducts pick up unconditioned air and moisture, so the system runs longer without any change at the thermostat.

The attic. In a Zone 3A summer, attic temperatures run well above outdoor temperatures, and that heat conducts straight through the ceiling. Thin or settled insulation up top means your air conditioner is fighting the roof all afternoon.

Air leaks. Rim joists, plumbing and wiring penetrations, top plates, and the gaps around them add up fast. In our evaluations across Greer, Taylors, Mauldin, and Easley, the leaks themselves are often a bigger problem than the insulation level — the house isn’t just under-insulated, it’s unsealed.

The Honest Savings Range: 20 to 40 Percent

Here’s the number we give homeowners, framed the way it deserves to be framed: homes we insulate and air-seal typically see 20 to 40 percent lower heating and cooling costs, depending on the home’s starting condition. That’s a range, not a promise. A 1960s ranch in Easley with fallen crawl-space batts and open foundation vents starts at one end of it. A tighter, newer home in Simpsonville starts at the other. Where your house lands depends on what we find — which is why we evaluate before we quote, and why you should be skeptical of any contractor who guarantees a fixed percentage before they’ve looked at your house.

Why Air Sealing Matters So Much in Climate Zone 3A

Greenville sits in IECC Climate Zone 3A — humid subtropical — in the Piedmont, up against the Blue Ridge foothills. In this climate an air leak costs you twice. Conditioned air leaks out, and humid outdoor air leaks in — and your air conditioner has to dry that air before it can cool it. That moisture load is a large share of what your system fights from May through September, and it never shows up on a thermometer. Spray foam matters here because it insulates and seals in one pass: it fills the cavities and gaps that fiberglass batts leave open, cutting both heat transfer and humid-air infiltration with a single material. In Zone 3A, that second job is often the one that changes the bill the most.

Duke Energy Rebates and What to Expect

Duke Energy serves most of the Upstate and offers rebates for qualifying insulation and air-sealing work. The amounts vary by measure and change from year to year, so confirm the current amounts before you schedule — we’ll point you toward the right program during your estimate. On the federal side, one correction worth making: the 25C energy-efficiency tax credit expired December 31, 2025, and no federal insulation tax credit currently applies. If someone promises you one, they’re behind on the news. Incentives are a bonus on top of the savings, not the reason to do the work — the lower bill is the reason.

What the Work Costs

Spray foam is priced per board foot — one square foot of coverage at one inch thick — so the total depends on the thickness applied and the area we cover. Open-cell spray foam runs $1.00 to $1.60 per board foot installed; closed-cell runs $1.60 to $2.60 per board foot installed. Two inches of closed-cell costs roughly double the single-inch rate before prep or removal of old material. Access, existing conditions, and scope all move the final number, which is why we quote only after an on-site insulation evaluation — never sight unseen.