Wall Insulation in Oklahoma City, OK

Wall insulation in a house under construction and wall insulation in a finished home are almost different trades. With the studs open, we can spray foam into every bay and see exactly what we have done. With drywall in place, the insulation has to go in through small holes and fill cavities we cannot see. Around Oklahoma City we do both: new houses, additions and garage conversions on one side, and older homes with empty or slumped wall cavities on the other.

New construction and additions

Oklahoma's code for Climate Zone 3 calls for R-13 in wood-frame walls, per the Insulation Institute summary of the state's amended 2018 IECC. That is a floor, not a target. In open stud bays, spray foam fills around wires, boxes and pipes and seals the joints at the top and bottom plates and around windows, which is where framed walls leak the most air. Open-cell foam is the common choice in 2x4 and 2x6 exterior walls here; closed-cell is used where we want more R-value in a thin wall, more rigidity or a vapor retarder. Fixr lists new construction spray foam at $2.75 to $6.50 per square foot.

Existing walls

Plenty of metro houses, especially those built in the postwar boom, have walls with little or no insulation, or old batts that have sagged. For those, the usual options are dense-packed cellulose blown through small holes in the siding, brick mortar joints or drywall, or a slow-rise injection foam. HomeGuide lists blown-in for exterior walls at $1,900 to $7,800 and dense-pack cellulose at $1.60 to $4.20 per square foot. Fixr puts spray foam in existing walls at $3.15 to $7.50 per square foot. The holes are patched afterward, but on brick or painted walls the patches may need touch-up.

Which walls to do first

Not every wall needs work. We often start with the walls that face west and south, which take the afternoon sun, walls of rooms over garages, and walls between the house and an attached garage. We check a few cavities with an inspection hole or a thermal camera to see what is there before we recommend anything.

Interior and sound walls

Open-cell foam also deadens sound, so homeowners sometimes add it to bedroom, bathroom and media room walls during a remodel. It is not as effective as purpose-built sound assemblies, but it helps, and it costs less than many people expect when the walls are already open. Get a free estimate