Spray Foam Insulation in St. Petersburg, FL

Spray foam insulation in St. Petersburg is mostly about keeping heat and humidity out. The city averages about 52.48 inches of rain a year under its 1991 to 2020 normals, with August the wettest month at 9.33 inches, and cooling runs for most of the year. A leaky attic lets superheated air and moisture into the house, and ducts in that attic pick up heat before the air ever reaches your rooms. We seal those leaks and insulate with open-cell or closed-cell spray foam where it pays off, and with blown-in insulation where it reaches the same result for less money.

What the Florida code asks for

The Insulation Institute's summary of the 2023 Florida Building Code, Energy Conservation (8th edition, effective December 31, 2023) lists R-38 for ceilings, R-13 for wood-frame walls and R-6 on the interior or R-4 continuous for mass (block) walls in Climate Zone 2. Only Broward, Miami-Dade and Monroe counties fall in Zone 1, so Pinellas County is Zone 2. For existing attics, the Department of Energy suggests R-49 to R-60 if the attic is empty, or adding R-38 to R-49 over 3 to 4 inches of existing insulation.

The houses we work on

St. Petersburg's housing is older than many Florida cities. ACS figures on Point2Homes put the median home's build year at 1969, with about 22.6% of homes from the 1950s and about 9% built in 1939 or earlier. That means older bungalows from before World War II, a large stock of postwar ranches and plenty of 1960s and 1970s homes, often with thin attic insulation, leaky ceilings and ducts running through the attic. Low-slope and flat-roof sections, common on additions and Florida rooms, add another set of problems.

Roof deck foam or attic floor

When the air handler and ducts are in the attic, spraying foam on the underside of the roof deck creates an unvented attic, so the ducts sit in air close to indoor temperature. When the attic is empty of equipment, sealing the ceiling and blowing cellulose or fiberglass deeper on the attic floor is usually cheaper. We look at your attic and compare both in writing.

Closed cell vs open cell

Open-cell foam is soft and vapor-open, about R-3.5 to R-3.7 per inch according to HomeGuide, and is common on roof decks and in frame walls. Closed-cell foam is dense and water-resistant at about R-5 to R-7 per inch, and suits block walls, flat roofs, raised floors on the beaches and anywhere water could reach the foam. Each quote names the foam we would use and why.

Is spray foam insulation worth it in Florida?

For the right surfaces, yes. Foam pays off where it seals as well as insulates: roof decks over attics with ducts, frame additions, kneewalls, flat-roof sections and garages turned into living space. It is not always the best value on a simple vented attic floor. The Florida Building Code also limits foam plastic near the ground in very heavy termite areas and calls for a 6-inch inspection gap above exposed earth, so we keep foam where the code allows it.

After Helene and Milton

In September 2024, Hurricane Helene pushed the St. Petersburg tide gauge to 6.31 feet above mean higher high water, a record for the gauge, and Milton brought nearly 19 inches of rain to the city a few weeks later. Many attics took water through damaged roofs, and many beach and bayside homes took surge. Wet insulation usually has to come out before anything new goes in, and we check for it on every visit.

Spray foam insulation cost

HomeGuide's 2026 guide lists installed spray foam at $1.50 to $5.00 per square foot: $1.50 to $3.50 for open-cell and $3.00 to $5.00 for closed-cell. It puts foam on a roof deck at $1,500 to $9,000, about 1,000 square feet of foam at $1,500 to $5,000 and a whole house at $8,000 to $20,000, and notes many installers set a $1,000 to $2,000 or higher minimum. For a 1,500 or 2,000 square foot house, the cost depends on the roof deck and wall area sprayed, not the floor area. We measure first, and the written estimate is your price.

Choosing insulation contractors and companies

When comparing spray foam insulation contractors or insulation companies near St. Petersburg, ask each the same questions. What gets air sealed first? Which foam goes where, and why? What thickness and R-value are written down? How will the attic be ventilated, or sealed if it is going unvented? How will storm-damaged insulation be handled? How long should the household stay out after spraying (HomeGuide advises 24 hours or more)? If a search for spray foam insulation near me turns up a company that will not put those answers in writing, keep looking.

Duke Energy Florida attic rebate

Duke Energy Florida's posted prerequisites for its attic insulation program require a Home Energy Check within the prior 24 months, an existing attic averaging R-19 or less, and installation by a Duke-approved contractor; multifamily and manufactured homes are not eligible. If you are a Duke customer, check the program page and its contractor list before the job.

We work across St. Petersburg and south Pinellas County. In the city, older bungalows and postwar block homes need attic sealing and roof deck work. Gulfport, South Pasadena and Bay Pines sit on Boca Ciega Bay, where surge and salt air matter. Kenneth City and Lealman have compact mid-century homes. Pinellas Park, Seminole and Largo grew fast in the 1970s. The beach towns, St. Pete Beach, Treasure Island, Madeira Beach and Redington Shores, plus Tierra Verde, have raised homes, condos and the heaviest storm exposure. Each town page explains what is different there.