O'Fallon's fast-growing subdivisions from the 1990s through today are built on a pattern that creates predictable insulation problems: two-story homes with walkout basements, bonus rooms stacked above garages, and vaulted great rooms that run hot upstairs and cold in the basement no matter what the thermostat says.
St. Louis Spray Foam Insulation has been serving O'Fallon (63366) and the surrounding St. Louis area since 2012. We specialize in the jobs that matter most in your neighborhood: sealing and insulating the rim joists and band joists where the garage connects to the house, spray foam in attics that bake at 130-150 degrees in July, and the bonus room walls and cathedral ceilings that leak conditioned air year-round. We show up with fully insured crews, write estimates with R-value and thickness specs, and we know exactly what your house needs because we have seen hundreds like it.
Spray Foam Insulation in O'Fallon (63366)
O'Fallon's building stock tells the story. Your home was likely built between 1990 and 2020, which means it was framed with modern materials but often with insulation choices that do not account for the mixed-humid St. Louis climate. The attic runs extreme temperatures: baking in summer, freezing in winter. The bonus room over the garage has cathedral ceilings or knee walls that are either empty or filled with fiberglass that has settled and lost its R-value. The rim joists where the basement rim band meets the foundation are often uninsulated or poorly sealed, which is why the basement stays cold and the upstairs stays hot. Closed walls in the exterior frame have no insulation at all. And if your home sits on a crawl space rather than a full basement, moisture and humidity are constant problems.
Spray foam fixes all of these. Closed cell foam in the attic stops the air leaks that let conditioned air escape and outside air infiltrate. Open cell foam in the bonus room walls and cathedral ceilings seals the cavities without the weight or cost of closed cell. Injection foam into the walls reaches cavities that blown-in insulation cannot. Rim joist foam stops the cold air path from the foundation into the rim band and into the living space above. Our team has been doing this work in O'Fallon and throughout the St. Louis area for over a decade. We know the code, we know the climate, and we know your house.
Our services in O'Fallon
- Attic Spray Foam Insulation in O'Fallon · Open-cell roof-deck foam turns an attic that bakes at 140°F in July and freezes…
- Closed Cell Spray Foam Insulation in O'Fallon · Two-pound closed-cell foam delivers R-6.5 per inch with its own vapor retarder…
- Open Cell Spray Foam Insulation in O'Fallon · Half-pound open-cell foam air-seals attics and walls at a friendlier price per…
- Wall & Injection Foam Insulation in O'Fallon · Injection foam fills closed frame walls through small drilled ports…
- Crawl Space Spray Foam Insulation in O'Fallon · Closed-cell foam on crawl space walls and subfloors ends the cold floors of…
- Rim Joist & Band Joist Spray Foam in O'Fallon · Basement rim joists leak more cold air than almost anything in a St. Louis…
- Garage Spray Foam Insulation in O'Fallon · Garage ceilings under bonus rooms and walls shared with the house are…
- Metal Building & Barndominium Spray Foam in O'Fallon · Closed-cell foam stops a Missouri metal building from sweating in spring and…
- Commercial & New Construction Spray Foam in O'Fallon · Warehouses; offices; churches and production builders served on schedule.
- Insulation Removal in O'Fallon · Old blown-in and batts vacuumed out before any new foam goes in, never buried.
- Insulation Replacement & Re-Insulation in O'Fallon · The full reset: old material removed; gaps air-sealed…
- Air Sealing in O'Fallon · Top plates; can lights; chimney chases and attic hatches leak more heated and…
How a Job Works in O'Fallon
We start with a free on-site assessment. You walk us through the problem: the upstairs that will not cool, the basement that will not warm, the condensation in the attic, or the energy bill that has become unaffordable. We look at what is already there, measure the spaces that need foam, and explain what open cell and closed cell do and which one makes sense for your job. If there is old insulation that has to come out, we tell you that now. We give you a written estimate with R-value and thickness specs so you know exactly what you are paying for and what code requires at your address.
On the day of the work, we set up mechanical ventilation to manage the smell during cure. We spray the foam to the thickness and density your estimate specifies. For attics, rim joists, and bonus rooms in occupied homes, we establish a re-entry window of twenty-four to forty-eight hours so you can move back into those spaces safely. We do not rush the job or promise immediate occupancy. If we are removing old insulation first, that work happens before we spray, and we haul it away clean.
When we are done, your property is clean. We walk through with you, answer your questions, and leave you with documentation of what was installed and where.
Attic spray foam in O'Fallon typically runs from $1.50 per square foot for open cell to $1.20 per board foot for closed cell, depending on the R-value you need and the thickness we have to spray. A 1,500-square-foot attic might run $2,250 to $3,000 in labor and material. Rim joist and band joist sealing starts at $650 and goes up with the linear footage and the depth of the rim band. Wall injection foam for a closed exterior wall runs from $2 per square foot. Crawl space foam typically starts at $2,500. If you have old insulation that has to come out first, that adds $950 and up depending on the volume and the condition. The real cost drivers are the area to cover, the R-value and thickness your climate and code require, whether you choose open cell or closed cell, and whether existing insulation has to be removed before we spray. We give you a free estimate at (314) 912-1801 so you know the real number for your house.
✅ Written Estimates with R-Value & Thickness Specs, fully insured for work in O'Fallon and nearby areas.
