Types of Spray Foam: Closed Cell and Open Cell

Spray foam vs. the rest

Why we spray foam:

Fiberglass, cellulose, and rock wool slow heat down. Spray foam slows heat down and seals the leaks that let it out. Here's how they stack up.

Swipe sideways to compare every insulation type.

Feature	Spray foamWhat we install	FiberglassBatts or blown	CelluloseBlown-in	Rock woolMineral wool batts
R-value per inch	R‑4.2 to R‑7.14	R‑2.9 to R‑3.8	R‑3.2 to R‑3.8	R‑3.0 to R‑3.3
Air seal	✓Expands to seal every crack and gap	✕Air passes straight through the fibers	~Slows air but doesn't seal it	✕No air barrier on its own
Moisture and mold	✓Closed cell resists water, mold, and mildew	✕Absorbs moisture and loses R-value when wet	✕Absorbs moisture and can settle or mold	~Repels water but still lets damp air through
Settling over time	✓Bonds permanently, never settles or sags	✕Compresses and sags in walls and attics	✕Settles by up to 20%, leaving gaps at the top	~Holds shape but leaves cut-to-fit gaps
Structural strength	✓Closed cell adds over 200% wall racking strength	✕None	✕None	✕None
Irregular spaces	✓Conforms to wires, pipes, corners, and masonry	✕Leaves voids around obstacles	~Fills cavities, not open or vertical surfaces	✕Must be cut around every obstacle
Energy loss from air leaks	✓Eliminates over 40% of residential energy loss	✕Does not address air leakage	✕Does not address air leakage	✕Does not address air leakage

R-value measures resistance to heat flow per inch of thickness. Higher is warmer. We install both open-cell and closed-cell spray foam and will recommend the right one for your building in the on-site assessment.

Types of spray insulation

Closed cell and open cell: two foams, two jobs.

We install both and recommend the right one for your building in the on-site assessment.

Closed cell R-7.14 per inch

High-performance thermal and structural insulation. This expandable polyurethane foam stands out for its closed-cell structure, which makes it denser and more rigid than its open-cell counterpart. Applied to walls, roofs, foundations and other strategic areas, it protects against the elements and raises energy efficiency. It does not retain water, mold, mildew, dust or other airborne particles, so it suits most installations.

Highest R-value per inch. Closed cell has one of the highest R-values per inch of any insulating material available and eliminates heat loss through its high closed-cell content. With it we can meet the new stretch code in a 2x4 stud wall.
New and retrofit construction. Spray-applied, it forms a continuous, monolithic insulation and air barrier on walls, around corners and on contoured surfaces, and adheres to masonry, stone foundations and below-grade applications.
Stops air leakage. It exceeds the requirements of a Type III air barrier as proposed by NRCC. The Department of Energy has documented that more than 40% of energy loss in residential construction is due mainly to air leakage; closed cell fills the cracks, gaps and small openings in the building envelope.
One-step application. Applied on site in a single step by trained contractors, it flows into cracks, joints and around protrusions, with no mechanical fasteners or adhesives. Confined work areas and unusual shapes are no challenge, which makes it the choice for air sealing attics, crawl spaces and hard-to-reach areas.
Structural integrity. Its high compressive strength adds to the structural integrity of stud wall construction; depending on the wall configuration, it can increase racking strength by over 200 percent.

Carlisle open cell R-4.4 per inch

We use a mid-weight product from Carlisle with an R-value of 4.4 per inch, which performs significantly better than products with lower R-values. It has a more rigid feel and needs less material to reach the target. It is excellent in walls and as part of a hybrid system in roofing, and while less expensive than closed cell it is the perfect partner in many installations.

Based in renewable natural resources, open cell expands to seal cracks, gaps and voids in attics, walls and ceilings, so builders and owners can use smaller, more energy-efficient heating and cooling units for the same comfort. International Code Council approved.

Seals and insulates in one application
Does not settle or compact in cavities
An air barrier thanks to its low air leakage
Contains no ozone-depleting chemicals and emits no toxic substances
Eliminates the growth of molds and mildew