Budgeting is a big part of any home improvement project – especially when it comes to determining the cost of foam board insulation, or any other material.

The cost to insulate your home with foam board insulation will vary depending on the size of your home, whether you hire a contractor or go the DIY route, as well as the cost of all the supplies you will need. Not every home is built the same or is even the same size, so for the purpose of this article we will give you an estimated price for the material and possible labor.

RetroFoam of Michigan has insulated thousands of projects across the lower peninsula and while spray foam and injection foam insulation is our specialty, we understand and know how other insulation materials work. In our continued efforts to educate homeowners, we are here to answer your questions about the cost of foam board insulation.

Foam Board Insulation Cost

The average house in the U.S. built in the 1970s is around 1,500-square-feet, so for this article we will use this average to determine the estimated cost of rigid foam board insulation from Home Depot.

R-Tech offers a rigid foam board insulation that can be used in the attic, exposed exterior walls, crawl space, or basement walls. This board is 2-inches thick and 4-feet x 8-feet with an R-Value of 7.7 and costs $18.48 per sheet at the time this article was written. To meet the building code, you will need a minimum of three layers.

• In the attic you would need 150 sheets, costing $2,772 before taxes.
• In exposed exterior walls you would need 120 sheets, costing $2,217.60 before taxes.
• In the crawl space you would need 60 sheets, costing $1,108.80 before taxes.
• The basement will require 120 sheets, costing $2,217.60 before taxes.

To insulate your entire house with this particular foam board insulation would cost between $6,099 and $8,316 depending on how your home is laid out. While a single layer won’t make building code, it’s still commonly used in small remodels.

This price is just an estimate based on the insulation needs of a 1,500-square-foot home. This estimate doesn’t include the cost of other materials needed including tape, caulk, utility knife, work gloves, or straight edge.

Do-It-Yourself Versus Hiring a Contractor

The estimate above covers just the foam board itself if you were to make it a DIY project. If you hired a contractor, you would pay about double that price to cover labor and material.

Hiring an experienced contractor is advised to save yourself the stress of a mishap and avoid damage to the home and to ensure the job is done correctly.

What is R-Value?

R-Value is an insulation material’s ability to resist the flow of heat.

While insulation with a higher R-Value can provide more heat resistance, it doesn’t tell the whole story. Heat flows in and out through radiation and convection. Heat loss through convection, or airflow, can account for nearly 40 percent of total energy loss in a home.

While on paper some insulation materials like spray or injection foam, have a lower R-Value than traditional insulation they do create an air barrier that other materials can’t accomplish.

Where to Use Foam Board Insulation

Rigid foam board insulation can be used in the attic roof deck, exposed exterior walls, crawl space walls or crawl space ceiling, and basement walls.

Foam Board Insulation Installation Process

Foam board insulation is designed to fit snuggly into stud cavities when cut properly.

The foam boards must be custom cut to fit the cavity where you plan to install it. If there are any gaps, you will be left with air movement that will make your home not only uncomfortable but cost you a fortune on monthly energy bills.

Once the boards are cut and ready to be installed, you will need to seal the seam between the boards. This can be done with special tape or caulk. You will need to ensure the seams are sealed so air can’t sneak in or out.

Insulating Your Home with Foam Board Insulation

The biggest decision you need to make now is whether this is something you think you can tackle on your own, or if it’s time to call in the professionals.

Do you research before you jump in. Look at what your contractor offers and what they do and don’t charge for. If you decide to make this a DIY project, do your homework first. The more information you have before starting the project can possibly save you a lot of money and headaches after everything is said and done.