Closed cell spray foam insulation is denser than its open cell counterpart and offers higher R-values, in addition to moisture resistance and structural integrity benefits that open cell doesn’t offer.
Polyurethane foams are created using two chemicals that interact to quickly expand into bubbles. Once cured, these bubbles tightly pack together and close off tightly for increased hardiness and durability in the final material.
R-Value
Closed-cell spray foam insulation is one of the two forms of polyurethane insulation and features dense structure that acts as an air barrier to keep conditioned indoor air inside while unconditioned outdoor air remains outside. When applied to wall cavities using an applicator nozzle and spray gun, closed-cell foam expands quickly once applied; its dense structure creating an effective air barrier between home comfort and unregulated outdoor air.
Sound dampening material like fiberglass insulation also has excellent soundproofing properties; in a two-inch installation it has an R value of up to R14 in 2×4 walls.
Closed-cell spray foam insulation may be more costly than open-cell options due to material costs and additional equipment needs, yet still costs less per square foot than batt-type or blown in insulations. Although more spray foam may be required to achieve an R-value equivalent than open-cell foam methods, ultimately it could end up costing about the same overall.
Moisture Resistance
Closed cell insulation foam is durable, sturdy, non-water absorbent material that’s great for fighting mold and mildew, stain-resistant and impervious to petroleum. Used extensively in flotation devices and homes with high moisture levels.
Though closed-cell spray foam insulation is effective at keeping out water vapor, it cannot withstand liquid water penetration if there’s a leak within its coverage area. This could present issues if leakage occurs within its confines as liquid would find a path through to cause additional damage if passing through foam insulation is allowed to happen.
Open-cell foam insulation allows moisture vapor to pass freely through its cells and into underlying materials, enabling leaks to be detected early and repaired before becoming major issues. Open-cell insulation is also flexible enough to get into tight places that closed-cell spray foam cannot, making it an excellent choice for attics, knee walls, crawlspaces and other hard-to-reach spaces.
Water Repellent
Closed cell foam insulation features tightly packed cells that resemble tiny air pockets. This type of dense material repels water, helping prevent moisture and vapor from entering through its porous structure, making it suitable for exterior walls or unvented attic assemblies.
These barriers do not permit water or vapor through, can reject bulk water and are FEMA approved for flood-prone areas. In addition, they are insect resistant and do not attract rodents or pests.
Open cell spray foam insulation features an open, bubble-like structure that allows it to expand more than closed cell foam can. When applied, open cell foam may expand up to 100 times its original size when applying and can fill nooks and crannies that would be hard to insulate with materials like fiberglass batts or cellulose; additionally it does an excellent job at dampening sound waves than its closed cell counterpart. When cutting this type of insulation it is advised that only non-serrated blade utility knives be used.
Structural Integrity
Closed cell foam insulations such as Icynene are rigid medium density insulators with added strength to exterior walls and stud cavities, helping resist compression that often occurs under structural load application.
Closed Cell Foam spray foam achieves high R-Value ratings per inch applied, because its cells are tightly sealed against airflow and tightly packed together, keeping its insulation properties intact and maintaining R-Value over time without becoming compressed and losing R-Value.
Closed-cell spray foam insulation is an excellent choice for retrofit or new construction homes and buildings. It adheres securely to most surfaces and creates a seamless permanent insulation system in walls, ceilings and attics. Closed-cell spray foam also makes an excellent addition for structures exposed to high winds; its stiffness helps minimize flexing of metal components like poles and beams while its water penetration resistance safeguards against bacteria growth as well as mold, rot and fungus growth.