Published 2026-10-02 · Sapulpa Spray Foam Insulation Kings

What Balloon Framing Means for Insulating Older Sapulpa Houses

Many houses built before the 1940s were balloon framed, meaning the wall studs run in one continuous piece from the foundation to the roof. That leaves tall, open wall cavities that connect the crawl space or basement directly to the attic. For insulation, it means air and heat move up through the walls like a chimney, and those openings have to be sealed and fire blocked before anything else.

How to Tell If Your House Is Balloon Framed

From the attic, look down at the tops of the exterior walls. In a balloon-framed house you may see open stud bays dropping straight down instead of a solid top plate. In the crawl space or basement, the bottoms of the walls may also be open to the cavities. Older two-story homes are the most likely, but some single-story houses from that era use it too.

Why It Matters for Comfort and Safety

Open cavities let warm air rise and escape into the attic while cold air is pulled in from below, which makes older homes drafty no matter how much attic insulation they have. The same open paths also let fire spread quickly from floor to attic, which is why modern codes require fire blocking at each floor level and at the top of the wall.

The Right Order of Work

• Fire block and seal the tops of the wall cavities from the attic.
• Seal the bottoms of the cavities from the crawl space or basement where reachable.
• Seal the rim joists and other penetrations.
• Then insulate the attic, with roof deck foam if ducts are up there or blown-in insulation on the floor if not.

What About the Walls Themselves?

If the walls are opened to the studs during a remodel, they can be fire blocked properly and filled with spray foam like any open wall. If the plaster is staying, standard spray foam is the wrong product for closed cavities. Dense-pack cellulose or a slow-rise injection foam made for closed walls are the usual options, after checking for knob-and-tube wiring and existing blocking.

Next Steps

A free estimate checks how your walls connect to the attic and crawl space and gives you a written plan. See attic spray foam insulation, wall spray foam insulation and our guide to insulating historic homes with plaster walls.