Sprayed Foam Insulation

Sprayed Foam Insulation

From: P.Shea

I am building my house in NJ in April. I want to use spray foam instead of fiberglass to insulate.

Could you give me your input on the process since I will be the GC?

Thanks

Hi P. Shea,

I've always used the "pink stuff" myself, but this really looks interesting.

Spray foam can be used as an insulating and air sealing product for residential wall and ceiling cavities. The insulation is sprayed, via special equipment, into wall cavities and expands to fill all the nooks and crannies in a wall cavity. Excess foam is scraped off the studs to form a uniform wall cavity.

Spray foam insulation makes it easy to completely fill wall cavities with insulation and to perform air sealing in the same step.

There are two types of spray foam: open-cell (isocyanurate) and closed cell (polyurethane). The closed cell foams typically have a higher R-value than open-cell foam.



Benefits/Costs:

Sprayed foam materials cost more than traditional fiberglass batt insulation. However, since sprayed foam forms both an insulation and an air barrier, it can be cost competitive with batt insulation because it eliminates the steps for air-tightness detailing (such as caulking, applying housewrap and vapor barrier, and taping joints).

As a result, it also reduces construction time and the number of specialized contractors.

Installation of spray foam insulation requires a skilled installer. Most products are readily available.

The installed cost for sprayed foam insulation runs about $1.25 to $2.25 per square foot, depending on wall thickness and type of foam.

Spray foam insulation is ideal for filling small spaces such as window jambs, small stud bays, rim joist areas, and for sealing around electrical boxes and other penetrations where cutting fiberglass batt insulation to fit can be difficult and labor-intensive.

Many sprayed foams are environmentally friendly. Most of them do not contain HCFCs that are harmful to Earth's ozone layer, or off gas formaldehydea potentially harmful volatile organic compound. Polyurethane foam insulation has about twice the R-value per inch of traditional batt insulation, making it more energy efficient in a smaller space.

Here's a video on installation:

Stay warm,
Carl

Source: NAHB Research