Block & Frame Wall Insulation in St. Petersburg, FL

Block and frame wall insulation covers the two main wall types in St. Petersburg. Many postwar homes are built of concrete block, often with thin furring strips and a little foil or foam board behind the drywall. Older bungalows, additions, Florida rooms and second stories are usually wood frame, sometimes with little or no insulation in the walls.

Block walls

The 2023 Florida energy code lists R-6 on the interior or R-4 continuous for mass walls in Zone 2. Block walls are usually insulated from the inside during a remodel: closed-cell foam sprayed on the block between furring strips, then covered with drywall. Closed-cell suits block because it does not absorb water and resists vapor.

Frame walls

The code lists R-13 for wood-frame walls in Zone 2. When frame walls are open during a remodel or addition, we spray open-cell or closed-cell foam. When they are closed, we dense-pack cellulose or fiberglass through small holes. HomeGuide lists dense-pack cellulose at $1.60 to $4.20 per square foot.

Additions and Florida rooms

Additions and enclosed porches are often the least comfortable rooms in the house. They may have thin walls, a low-slope roof with little insulation, and gaps where they meet the original house. Foam in the walls and ceiling, and sealing the joints, usually fixes them.

Termite rules

The Florida Building Code restricts foam plastic on the exterior of foundation walls in very heavy termite areas and calls for a 6-inch inspection gap above exposed earth. Interior wall insulation is not affected the same way, but we keep the rules in mind.

How we check walls

We look behind outlet covers, check the attic and sometimes drill a test hole before pricing.