NORTHWEST HOUSTON Blog

What is Spray Foam Insulation?

Spray polyurethane foam (SPF), or more commonly called spray foam insulation, is a spray-based plastic material used to seal cracks and gaps and insulate a building.

SPF comes inside a can or a container and starts in liquid form. Once sprayed, the material expands permanently and hardens to a plastic foam. It takes the shape of the surface it makes contact with, making sure to seal every nook and corner.

Materials commonly used in a spray foam

Spray foam is a mixture of two primary components: isocyanate and polyol resin. The reaction between the two chemicals give birth to polyurethane, a durable and flexible material with great tear-resistance and a low thermal conductivity, making it an ideal sealant and insulating material.

Spray foam works two ways: a sealant and an insulator 

As a sealant 

Spray foam available in cans is a one-component spray foam used for sealing cracks and gaps found in walls, windows, doors, around recessed lights and electrical outlets.

With spray foam insulation, two components are mixed on-site. This two-component spray foam is used for extensive air sealing in attics, ceilings, joists, and studs.

This tight material blocks all air from entering, creating a virtually airtight seal in your home.

As an insulator 

Spray foam insulation is suitable for newly-constructed buildings with unfinished components or even older homes looking for an insulation upgrade. The insulation is applied to the open walls, exterior walls, attic joists, and ducts. 

Spray foam can also be installed on existing walls by stripping a part of the drywall. What happens next is a hole is drilled on the wall where our crew will inject the foam inside the cavity.

Spray foam has an average of thermal conductivity ranging from 0.022 to 0.035W/m?K. The lower the thermal conductivity, the more difficult it is for heat to conduct to this material, making spray foam insulation an optimal choice for insulation.

Two kinds of spray foam:  

Closed-cell spray foam

Closed cell spray foam is composed of densely-packed cells, hence its name. It has an R-value of  ~6.9 per inch, offering a high resistance against heat. 

It is a champion in sealing against air and water. This insulation offers considerable soundproofing abilities and high resistance to fire (when mixed with a thermal barrier).  However, it is important to note that while closed-cell foam is an effective vapor barrier, it still must be protected from getting wet. Moisture can be retained near the structures and cause moisture problems.

Closed-cell spray foam doesn’t expand as much as open-cell foam, making it an ideal insulation choice if you have tight or limited spaces in your home or building.

It is also the only insulation that adds strength to structures it has made contact with.

Open-cell spray foam

A highly expansive foam insulation that can scale up to 100 times. Once applied, it expands widely and provides more coverage than the closed cell spray foam. 

Open-cell spray foam has an R-value of ~3.7 per inch. 

Along with cellulose insulation, open-cell foam is one of the top insulation that offers superior noise reduction. Combined with a thermal barrier, it provides a good fire resistance.
 

In Houston, you will find more open cell spray foam in the attics of a house. You will find closed cell under a house for moisture barrier/crawl spaces or structures such as barns. The closed cell helps with rigidity. 

Why should I choose spray foam insulation?

Spray foam insulation acts as a sealant and insulation in one, trapping air and heat from entering and exiting a building, making it energy-efficient and comfortable.

Spray foam insulation can last you the duration of your home. Unlike other insulation, spray foam does not sag or settle over time. This synthetic material isn’t attractive to rodents, keeping pests at bay and prolonging your insulation.

To ensure effectiveness and safety of spray foam insulation, only certified and trained professionals should perform the installation. At Koala Insulation we have our experts who can help you with installing spray foam the right way. Book your free insulation evaluation with one of our consultants today!.