Concrete Block Wall Insulation in Lakeland, FL

Concrete block wall insulation is a Florida specialty. Many Central Florida homes have exterior walls of concrete block, and the Florida energy code treats them separately as mass walls. Block stores heat. On a summer afternoon, a west-facing block wall absorbs sun for hours and keeps releasing that heat into the house after dark. A thin layer of foil-faced furring or nothing at all on the inside does little to stop it.

What the code says

Florida's 8th Edition energy code, in effect since December 31, 2023, lists R-13 for wood-frame walls in climate zone 2, and a lower value for mass walls, between R-4 and R-6 depending on whether the insulation is continuous or on the interior, according to the Insulation Institute's summary. That reflects the heat storage of masonry, but older block homes often have far less than even that.

How we insulate block

The practical time to insulate block walls is during a remodel, when the drywall comes off. With the furring strips exposed, closed-cell spray foam sprayed between them bonds to the block, seals cracks and penetrations, and gives the most R-value in the shallow space. Fixr lists spray foam in existing walls at $3.15 to $7.50 per square foot. For new furring, the depth of the strips decides how much foam fits.

Moisture and block

Block can wick moisture from rain. Closed-cell foam slows vapor movement from the wall into the room, and it is not harmed by occasional dampness. We still check for leaks at windows, cracks and roof-wall joints before covering anything.

Frame additions and gable walls

Many block homes have wood-frame gable ends, second floors or additions. Those can be foamed or blown in like any frame wall.

Get a free estimate or call (863) 341-8561 to talk about your walls.