Spray Foam Insulation in Clearwater, FL

Spray foam insulation is sprayed as a liquid, expands to fill gaps and cracks, and cures in place, so a single layer both insulates and stops air. In a Clearwater house that air seal matters as much as the R-value: the Tampa airport's 1991-2020 climate record shows a year-round average relative humidity of 74.1%, and every leak in the ceiling or walls lets that damp air in for the air conditioner to deal with. We spray two kinds of foam, and the first decision on each job is which one goes where.

Open cell vs closed cell

Open-cell foam cures soft and spongy. HomeGuide rates it at about R-3.5 to R-3.7 per inch, and it expands many times its sprayed volume, so it fills irregular rafter bays and around wiring easily. It blocks air very well and dampens sound, but water vapor can pass through it, and it will soak up liquid water. It is the less expensive of the two per square foot.

Closed-cell foam cures hard and dense at roughly R-5 to R-7 per inch. At normal thickness it slows vapor to a crawl, takes on very little water and adds some stiffness to what it is sprayed on. It costs more per inch but gives more R-value in a shallow space.

Where each one fits in a Pinellas home

On the underside of a pitched roof deck over a typical attic, open-cell is common: there is room for the depth, and its lower cost per square foot adds up over a full roof. Closed-cell is the usual pick where water or space is the issue: low-slope roofs with shallow rafters, the inside of concrete block walls, garage ceilings under a bonus room, cantilevered floors and small cavities where a few inches has to reach a target. On some jobs we use both, for example closed-cell at the roof edges and open-cell across the field of the roof.

Code targets we size to

The 2023 Florida Building Code, Energy Conservation lists R-38 for ceilings and R-13 for wood-frame walls in climate zone 2, which covers Pinellas, Pasco and Hillsborough counties, and R-6 on the interior of mass (block) walls. Foam is not always installed to those numbers in retrofits, because the energy code applies differently to existing homes, but we use them as the reference, and the quote states the thickness and R-value for each area so you can see where it lands.

The unvented attic question

When foam goes under the roof deck, the attic becomes part of the conditioned house instead of a vented space. Florida's residential code covers this in section R806.5, the rules for unvented attic assemblies. In practice it means the soffit and ridge vents are closed off, the foam is installed to the right type and thickness, and the attic shares air with the house. Done properly, it pulls the air handler and ducts out of a space that can run far hotter than outdoors on a summer afternoon. Done poorly, it can trap moisture against the roof sheathing, which is why we walk you through the plan.

When foam is not the answer

Foam does not fix a leak; a roof or plumbing leak has to be repaired first, or wet wood ends up hidden behind it. On an open attic floor with ducts elsewhere, air sealing plus blown-in fiberglass or cellulose usually reaches the same R-value for less money. Old wiring, damaged ducts or suspect materials get checked before anything is covered. If we see any of these, we say so before we price.

Prep, cure time and reentry

Spraying goes quickly; the setup takes longer. We cover floors and belongings, mask what needs masking and ventilate the work area. HomeGuide advises leaving the house for 24 hours or more while foam cures. Once cured, foam does not settle, so the thickness you pay for is the thickness you keep.

Tell us which spaces you are thinking about and what you have noticed, and we will look, explain where foam is worth it and send a written price. Get a free estimate