crawl space insulation cost

Average Cost for Crawl Space Insulation

The average cost to insulate a crawl space is $1,950 or $1.95 per square foot for a 1,000 square foot crawl space. Many homeowners choose to insulate their home’s crawl space themselves, which saves on labor costs but might come with it the cost of tools in addition to insulation and materials. If you hire a professional to insulate your crawl space, he or she will clear away old insulation, prepare the crawl space for new insulation, complete the installation and clean up any leftover debris.

Last Updated: Thursday, April 7, 2022

Overview of Crawl Space Insulation

Crawl space, aka crawlspace, insulation keeps the area warmer in winter, which means the living space above it stays warmer too. The main reason homeowners take on this project is energy efficiency. Insulating your crawl space saves money on heating and cooling costs and keeps your HVAC system from overworking. But home comfort is important too.

This cost estimate looks at the cost factors involved in insulating a crawl space, types of insulation and their functions, and we also offer some DIY tips and materials to consider.

We do recommend this as a good DIY project if you are okay working in small spaces and getting a little dirty. If you don’t mind spending some quality time in your crawl space, the insulation process itself is fairly straightforward.

Product and Installation Supplies Cost Details

Crawlspace Insulation Cost Factors

The list of cost factors below is to help you know what to consider before beginning this project. The cost of insulating a crawl space can be as little as $0.95 per square foot if you DIY and stay thrifty with your materials. On the higher end, crawl space insulation can cost $2.80 or more per square foot for professionally installed, high quality insulation, especially with a high R-value, or resistance to heat transfer. This list of cost factors will help you home in on your project and form an accurate cost estimate.

• Type of Insulation – There are three types of insulation that are used for a crawl space. Listed below is each type with its function. Most projects require more than one type.
  • Fiberglass Insulation: Also known as batt, blanket and roll insulation, fiberglass insulation is the fluffy pink material that comes in rolls. Fiberglass insulation works best between floor joists on the “ceiling” of a crawl space. It is commonly used  in crawl space rim joists too. This is the least expensive type of insulation, but it tends to soak up unwanted moisture. R-value ranges from about R-13 to R-30, or about R-2.7 to R-3.0 per inch.
  • Foam Board Insulation: Foam board insulation is affordable and good for big spaces. Three types of rigid foam boards are popular for crawlspaces. Polyisocyanurate, or poly-iso, is the costliest but wins the R-value battle with an R-6.8/inch rating. XPS, or extruded polystyrene, is next with an R-5 value per inch. Expanded polystyrene (Styrofoam) costs the least and has an R-Value of about 3.8/inch. Foam boards are great for big spaces, but they don’t work in small spaces or cracks.
  • Spray Foam Insulation: Spray foam insulation comes in two types. Closed cell spray foam insulation is waterproof, seals really well and has an R-value of 6.5/inch. Ideal for sealing around windows, vents and other openings, it can also be sprayed on walls of the crawl space. It’s the insulation of choice for crawlspace encapsulation too because it seals far better than other insulations. Open cell spray foam saves money, and if your crawl space isn’t damp and you don’t need the high R-value, it’s worth considering – with R-3.5 insulation value.
• Insulation Level – The recommended insulation level for crawl spaces in the United States is R-19, though in mild climates you may be able to get away with R-13 or R-15. The higher the insulation level, the more it will cost.
• Size of Crawl Space – This cost estimate uses a 1,000 square foot crawl space as an example, but a bigger crawl space will require more materials and labor.
• Crawl Space Condition – How does your crawl space look? If there is a lot of debris, old insulation materials, mold, or any rotting wood, you’re going to need to do some prep work before you can begin insulating. If you spot any mold, make sure to call in an expert to remove it so that you and your household are protected.
• Who Does the Installation – If you are going to hire a contractor to insulate your home’s crawl space, you can expect to pay about $0.60 – $1.25 per square foot for labor alone. If you’re planning to DIY, you will save money on labor costs, but you’ll need to purchase a few tools like a tape measure, utility knife, stapler, dust mask, gloves, and safety glasses.

Retail Crawl Space Insulation Costs

Here are retail costs for the type of insulation discussed above.

• $0.30 – $0.40 per square foot | R-13 Fiberglass Rolls/Blankets/Batts
•  $1.35 – $2.50 per square foot | 1”, R-6.8 Polyisocyanurate Rigid Foam Boards
•  $0.58 – $0.70 per square foot | 1”, R-5.0 XPS Rigid Foam Boards
• $0.40 – $0.50 per square foot | 1”, R-3.0 EPS Rigid Foam Board
•  $0.55 – $0.70 per square foot | 1”, R-3.5 Open Cell Spray Foam Insulation Kit
•  $0.95 – $1.25 per square foot | 1”, R-6.5 Closed Cell Spray Foam Insulation Kit
• $6.00 – $12.00 per can | Expanding Spray Foam Insulation – Ideal for use around crawl space opening

Permits, Inspection, Related Costs and Installation Time

Permits and Inspection Cost

• $0 | Insulating a crawl space does not require a building permit when no structural changes are made to the area.

Related Costs and Installation Time

• 4 – 8 hours | A professional crew of 2-3 people will be able to insulate a crawl space in a matter of hours, while a homeowner with less experience may need a full workday to complete the project. Add an extra hour or two if you have significant prep work to do in your crawl space before beginning.

Related Projects

• Cost of Crawl Space Encapsulation
• Cost of Vapor Barrier in Crawl Space
• Interior Basement Sealing
• Sump Pump Installation
• French Drains in Crawlspace or Basement
• Cost of Block Foundation Repair
• Mold Removal

DIY or Hire a Pro?

Insulating a crawl space is a project that will grow your skills as a homeowner and save you some money on labor costs. How much can you save? Homewyse puts labor at about 50 cents to $1.20 per square foot. Porch suggests a little lower labor cost at up to $1.00 per square foot. There is not a lot of technical skill required, so if you have the work ethic, you can do this!

DIY is not for everyone, and there are many homeowners who aren’t interested in spending that much time in their crawl space. We get it. That’s why we offer a tool that helps you get free, no-obligation cost estimates from contractors near you.