Tampa Spray Foam Company breaks attic insulation cost into two approaches. Topping up the attic floor with blown-in fiberglass or cellulose typically costs about $1.00 to $2.80 per square foot, while spraying foam under the roof deck puts most existing homes somewhere around $3,000 to $8,000. Pulling out old insulation first adds roughly $1 to $2 per square foot.
The code target is R-38, the prescriptive ceiling level in Florida's 8th Edition energy code for our climate zone. It's also the finish line Duke Energy Florida's attic rebate asks for.
Which approach makes sense depends mostly on what shares the attic with the insulation. In Florida homes the ducts are almost always up there, sometimes with the air handler, and that changes the math. Our crew sprays foam, but if a blown-in top-up is the smarter buy for your house, we'll tell you at the estimate.

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Foam and blown-in quotes for the same house won't use the same square footage, because foam is measured on the sloped deck while blown-in covers the flat ceiling below. They're national installed ranges; we couldn't find Tampa-only price data.
Hillsborough and Pasco are in Climate Zone 2, where Florida's 8th Edition code sets R-38 for ceilings, and the 9th Edition, targeted for Dec. 31, 2026, shows R-38 in its beta form. Foam at the roof deck is judged differently, as our open cell vs. closed cell page explains.
Blown-in is the cheaper road to R-38, and for some homes it's the right one. The attic stays vented and hot, though. In an FSEC field study of Fort Myers homes, the dark-shingle control house's attic reached about 110°F on a typical summer day. A Cocoa test home with a radiant barrier and roughly R-19 on the ceiling logged attic air as hot as 136°F. Sending cold air through ducts in that space is like carrying a cup of ice water across a Tampa parking lot in August.
Foam on the deck pulls the attic inside the home's thermal envelope, so the ducts sit in far cooler air and any duct leaks still land in conditioned space. In FSEC's sealed-attic test home, with 5 inches of open-cell, no ceiling insulation and dark shingles, the attic topped out at 83°F and cooling energy dropped 6 to 11 percent, with little change at peak. Results aren't automatic, though. A 2020 study with ducts in both attics found the sealed one warmer, with 8 percent higher cooling energy than the vented one, which is why we don't quote savings figures.
Earlier research cited by FSEC found attic heat gain to ducts can raise cooling loads by up to 30 percent at summer peaks. In a 48-home Central Florida study, homes whose air handler sat in the attic burned 30 percent more cooling energy than homes with the unit in the garage or somewhere else.
Leaks add to it. In a study of 91 Florida homes, return leaks averaged 10 percent of air handler flow, the authors estimated half or more of them came from the attic, and duct repairs cut cooling energy 18 percent on average.
In our experience, an attic holding the ducts and the air handler is the strongest case for foam at the deck. If your ducts leak badly, though, sealing them can be the cheaper first step: TECO offers duct repair through approved contractors for $125 after a pre-approval inspection, and Duke's program covers duct testing and repair up to $450.
Removal runs about $1 to $2 per square foot, disposal included. It's worth paying for when the old layer is matted, wet or fouled by rodents, or when it blocks air sealing at the ceiling. It isn't automatic. If we're foaming the deck and the ceiling insulation is clean, leaving it in place can be the better call. FSEC has recommended that Florida's R-20 sealed-attic path require at least R-11 of ceiling insulation, with narrow exceptions, and its sealed-attic test home did see more heat move through the bare ceiling.
TECO's rebate is $0.16 per square foot per R-11 added over conditioned space, stackable in R-11 steps, for homes with electric whole-house cooling or heat. Adding R-22 over a 1,500-square-foot ceiling, for example, comes to $480. A TECO analyst inspects the attic before work begins, and you have 90 days after installation to apply. The program is built around ceiling insulation, so whether roof-deck foam qualifies under current rules is something we'll confirm with TECO for your project. Homes in qualifying low-income areas may get attic insulation at no cost through TECO's Neighborhood Weatherization program.
Duke starts with a free Home Energy Check. If that audit recommends attic insulation, the single-family rebate is tiered by what's up there now, provided the existing layer averages R-19 or less and the finished attic reaches at least R-38:
The audit has to be from the past two years, and Duke's rules don't mention spray foam. Homes in Zephyrhills and southwest Pasco are usually on Duke, while much of central Pasco is on WREC, which has no insulation rebate we could find.
A free on-site estimate shows which approach fits, the thickness and R-value, whether old insulation goes, and which rebate paperwork applies. Most foam attics take one day, and you'll stay out for at least 24 hours, or longer if the manufacturer requires it. For per-foot pricing on foam, see what spray foam costs in Tampa, browse our spray foam services, or schedule your attic estimate.
Book a free attic estimate and get the R-value and thickness in writing.