Where and When to Use Spray Foam Insulation

Spray Foam insulation forms alternative to traditional insulation materials such as fiberglass insulation. The material can be used during planning or even in the construction project. Spray foam is an expandable foam substance which can be easily sprayed into wall cavities during construction or onto a roof for insulation purposes.

Spray foam insulation applied by an attic insulation contractor wearing proper PPE

Spray Foam insulation being applied to bare wood in attic

Cost of the Spray Foam Insulation

The material is available in two forms. You can use open cell spray foam insulation which is usually $0.44 to $0.65 per board foot. Closed cell spray insulation is about $1 to $1.50 per board foot. The average labor cost to have spray foam professionally installed is about $2,104. The amount can vary depending on whether the home is new or old. A finished home will likely require energy audit or weatherization instead of spray foam insulation.

We are going to cover sections such as:

  • Where to Use Foam Insulation
  • DIY Foam Insulation Kits
  • Types of Foam Insulation
  • R-Value and Thermal Resistance
  • Benefits and Disadvantages
  • The difference in Cost for New vs. Existing Homes


Where to Use Spray Foam Insulation


You can use spray insulation to achieve both vapor and air barrier depending on the depth used. You should carry out checks and confirm the brand of foam used before hiring a contractor. It is necessary to check the manufacturer’s name, as well as the ESR reports and MSDS sheets on the foam, is installed. Some of the areas which are suitable for the insulation include:

Crawl Space/Basement:

In this area, you can apply it on spray foam seals pipes, cracks, plumbing, sills, and framing.


You can install the insulation around the heating and cooling system to optimize their performance. Areas you can apply it include around pipes, floor registers, condensers, and duct-work. Reductions experienced in extremely hot and cold climates can offset the upfront cost or the additions with foam.


Exterior uses for spray on insulation include:

  1. Electrical & gas penetrations
  2. Where the siding & Foundation meet
  3. Wall joints in the garage ceiling
  4. Stone wall repair
  5. Around exterior faucets and vents
  6. Securing block walls in the landscape
  7. Water feature fillers

You should choose closed cell or open cell spray insulation based on the purpose and the placement of the insulation. Always pay attention to the recommendations of the insulation contractor.


Types of Insulation and Their Benefits

Insulation Benefits

It is important to insulate the attic irrespective whether you are converting it or not. Insulation can save up to $600 in cooling and heating costs. There are several forms of insulation to choose. They include batts, blown in, barriers and spray foam. They have their pros and cons.

White spray foam being applied inside the roofing rafter

Contractor applying spray foam insulation in an attic.


They are made out of fiberglass or cellulose which is packed in rolls of varying thickness. To install you have to part with $1,500 on average. The large rolls can fit between studs and fill voids to prevent air from leaking into and out of the exterior wall. It costs $0.60 to $1.20 on average per square foot. It works best where attic has few obstructions.


You can choose between reflective or radiant barriers which can cost an average of $1,600. The insulation applies thermodynamics to increase your home’s R-value. The value represents the ability of attics to resist heat flow. The barriers work through absorbing and reflecting heat so that they can maintain moderate temperatures. The attic insulation is best in homes located in areas with warm climates. It can cost an average of $0.17 to $0.33 per square foot.

Blown-in Insulation

It costs about $1,346 to install. It is known to offer perfect insulation with high R-value. Blown insulation can cost an average of $0.26 to $0.62 per square foot. You will have to part additional $64 to $80 per hour in labor. The blown in insulation consists of white cellulose which is a paper like material manufactured from recycled cardboard and newspapers. The insulation allows easy installation in tight spots. It is also pest and moisture proof.

Spray Foam Insulation

The insulation can cost an average of $1,900. There are two types which include closed cell and open cell foam. Both can work well, but closed foam offers high R-value, in addition to the insulation being vapor and water barrier. There is also an added benefit of sound proof when you use closed cell foam insulation. It is the perfect option for attic floor insulation. Open-cell foam can cost an average of $0.40 to $0.55 per board foot. For closed-cell spray foam, it can cost an average of $0.65 to $1 per board foot.