Closed cell spray foam is a dense, rigid foam that insulates, seals air leaks and keeps out moisture in a single layer. It packs more insulation into each inch than most materials, which makes it the right choice for tight spaces and metal buildings.
CAL FOAM Inc. installs closed cell foam in homes, cabins, shops, metal buildings and mobile home underbellies across Tulare County and the Central Valley. California contractor license #1123937.
When thermal performance, moisture control, and structural strength all matter — which describes most California commercial, agricultural, and industrial buildings — closed-cell spray foam is the highest-performing insulation option available. It delivers more R-value per inch than any other common insulation material, acts as a complete vapor and air barrier, and adds measurable rigidity to the building components it is applied to.
CAL FOAM Inc. specializes in professional closed-cell spray foam installation across California, from the Central Valley's agricultural heartland to coastal commercial buildings and inland industrial facilities. We are a licensed, owner-operated contractor — License #1123937 — with the equipment, training, and hands-on experience to deliver flawless installations on projects of any scale.
Closed-cell spray foam is a two-component insulation material that expands and cures into a rigid, dense foam. Unlike open-cell foam, the cells in closed-cell foam are completely sealed — each tiny cell is an isolated pocket filled with a blowing agent gas that provides superior thermal resistance. The result is a material with an R-value of approximately 6.5 per inch — roughly double the per-inch performance of open-cell foam.
More importantly, closed-cell spray foam is impermeable to both air and water vapor. It qualifies as a Class II vapor retarder under building codes, meaning it controls moisture migration through walls and roofs at the level required for most California climate zones. It also bonds permanently and rigidly to whatever surface it is applied to, adding measurable structural strength to wall panels, roof decks, and other building components.
The choice between closed-cell and open-cell foam depends on what the application requires:
Many projects use both — closed-cell on the exterior envelope and open-cell in interior partition walls. CAL FOAM Inc. will design the right system for your specific building during the free assessment.
|
Closed cell |
Open cell |
|
|
R-value per inch |
About 6 to 7 |
About 3.5 to 3.8 |
|
Feel |
Rigid and dense |
Soft and spongy |
|
Water |
Does not soak it up |
Soaks it up |
|
Water vapor |
Slows it at 1.5 to 2 inches |
Lets it pass |
|
Sound |
Some reduction |
Better at absorbing sound |
|
Cost per inch |
Higher |
Lower |
|
Best for |
Metal buildings, shops, underbellies, crawl spaces, containers and tight spaces |
Interior walls, attic roof lines and sound control |
Many projects use both: closed cell on metal and outside walls, and open cell inside. Learn more about open cell spray foam.
California's Title 24 energy code sets minimum insulation requirements for both residential and commercial construction. Closed-cell spray foam, with its high R-value per inch and integrated air barrier, is one of the most effective ways to meet or exceed Title 24 requirements — particularly in climate zones with higher wall R-value mandates. We document all installations with material data sheets and R-value calculations that can be provided to building inspectors and permit offices as needed.
Tyler H. needed his cabin insulated in a space with little room to work. We used closed cell spray foam to give the cabin a permanent air seal and moisture barrier. The foam also cut outside noise.
"The cabin stays at a constant temperature." Tyler H., Google review
Eva's older mobile home had rodents nesting in the insulation between the vapor barrier and the subfloor. The site was hard to work: sharp rocks, sloped ground and very little headroom. We removed and hauled away all the old insulation and vapor barrier, then sealed the subfloor and cross supports in hard spray foam.
"A very hard material thick enough to insulate." Eva, Google review
California's Title 24 energy code sets the minimum insulation for each part of a building. The target changes by climate zone and by whether the project is a new build or a remodel, so foam depth alone does not prove a building meets it. We give you the foam's data sheet and the depth we installed, for your inspector or energy consultant.
Ready to take the next step? Call CAL FOAM Inc. at (805) 225-3626 or visit calfoaminc.com to schedule your free on-site assessment. We serve Strathmore, Bakersfield, Fresno, Los Angeles, Sacramento, San Jose, Stockton, Anaheim, Riverside, Modesto, Turlock, Santa Barbara, San Luis Obispo, Paso Robles, Lancaster, Victorville, Napa, Santa Rosa, Redding, and communities across California. License #1123937.
Closed-cell spray foam achieves approximately R-6.5 per inch — compared to R-3.7 for open-cell foam, R-3.1 per inch for fiberglass batts, and R-2 per inch for rigid EPS foam board. In a 2x4 wall cavity (3.5 inches), closed-cell foam provides approximately R-22, exceeding Title 24 wall requirements in most California climate zones. Its air barrier properties further enhance real-world performance beyond what the rated R-value suggests.
Yes. Closed-cell foam can be installed in open wall cavities during renovation, on the interior of metal building walls and roofs, under existing roof decks from the interior, in crawl spaces, and in other accessible areas of existing buildings. It is particularly effective in retrofit situations because its high R-value per inch allows significant performance improvement without major structural changes.
In California, spray foam insulation left exposed in occupied spaces must be covered with a thermal barrier — typically 1/2-inch gypsum drywall or an equivalent fire-rated material. In some applications like crawl spaces and attics, an approved ignition barrier coating may be used instead of drywall. CAL FOAM Inc. handles all thermal barrier requirements as part of the installation scope.
Properly installed closed-cell spray foam has an indefinite service life under normal conditions. It does not degrade, settle, or lose R-value over time. The limiting factor is typically the building around it, not the foam itself. Most manufacturers expect well-installed closed-cell foam to last 30 years or more with no maintenance.
It depends on the application. For exterior walls, metal buildings, crawl spaces, and anywhere moisture control is critical, closed-cell is the right choice — not just the premium one. In those applications, open-cell foam is not an equal alternative because it does not provide vapor control. For interior partition walls and acoustic applications, open-cell is sufficient and more cost-effective. We will be direct with you about which product is appropriate for each area of your building.
Yes — and it actually provides a benefit. Closed-cell spray foam adds racking strength and structural rigidity to wall assemblies when it bonds to framing members. While it is not a substitute for structural engineering on buildings that require seismic design, it is a net positive for structural performance in wood-framed and metal-framed buildings.
On metal, in mobile home underbellies, in crawl spaces and in other tight or damp spaces, usually yes. Open cell foam cannot keep out water or reach the same R-value in a thin space. In standard house walls and attics, open cell often gives more value for the money, and we will tell you if that is the better choice.
It depends on the space and the R-value your project needs. At about R-6 to R-7 per inch, 2 inches gives roughly R-12 to R-14, and 3 inches gives roughly R-18 to R-21. We recommend a depth after we see the space.
In rooms you live or work in, yes. Code requires a thermal barrier such as drywall, or a tested intumescent coating, which we also apply.
Yes, wherever the framing or metal panels are open: shop walls, the underside of roofs, crawl spaces and mobile home underbellies. Finished walls have to be opened first.
Yes. Condensation forms when warm, humid air touches cold metal. Once the metal is fully covered with closed cell foam, the air can no longer reach it.
It does not sag, settle or soak up water, so it keeps working for the life of the building as long as it is protected from sunlight and physical damage.
The price depends on the area, the depth and how easy the space is to reach. We give free written quotes after we see the space.
Call (805) 225-3626 or email derek@calfoam.net to set up a free on-site visit. CAL FOAM Inc. is based at 19308 Orange Belt Dr, Strathmore, CA 93267, and serves Tulare County and the Central Valley. California contractor license #1123937.
Related services: Open Cell Spray Foam, Intumescent Fire Coating, Commercial Insulation, Residential Insulation