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How Much Does It Cost To Insulate A Crawl Space?

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National Insulation Costs

$0.56 per sq. ft. Minimum Cost
$1.32 per sq. ft. Maximum Cost

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How Much Does It Cost To Insulate A Crawl Space?

Insulating a crawl space can make the whole home more energy efficient. If not insulated, this area can let in drafts while heat escapes the house. An un-insulated crawl space can also be a haven for trapped moisture and mold growth. Although insulating a crawl space costs money, the energy savings are worth it in the long run.

If you're ready to insulate your crawl space, then use our free lead generator to contact an insulation pro in your area.

Table of Contents

  1. Crawl Space Insulation Cost
  2. Cost Considerations For Insulating A Crawl Space
  3. Types Of Crawl Space Insulation
  4. Significance Of Crawl Space Insulation
  5. Insulation Basics
  6. DIY Or Hire A Pro?
  7. How To Install Insulation In A Crawl Space
  8. Find A Pro

Crawl Space Insulation Cost

The cost to insulate a crawl space depends on the type of insulation you use. Purchasing common R25 batt insulation measuring 15 inches by 40 feet can cost anywhere from $151 to $354. This amount covers a 267-square-foot space. Initial labor costs for four hours of work could range from $112 to $274, and job supplies add an additional $33 to $37 for a total project cost ranging from $297 to $666. This amount can vary greatly depending on the type of insulation you use and the current condition of your crawl space.

Cost Considerations For Insulating A Crawl Space

Cost Considerations For Insulating A Crawl Space

There are many factors that play into the cost for insulating a crawl space, including the following:

  • Location: A crawl space is located either between the ground and the first floor or above the home in place of the attic. Overall costs can vary depending on where your crawl space is located. Ease of access may also affect costs if you hire someone to do this job — expect to pay more for labor if your crawl space is confined and difficult to access.
  • Size: The bigger the area that needs insulation, the higher the cost.
  • Type of Insulation: Fiberglass batt insulation is less expensive than spray foam insulation, but the difference in price does account for a difference in quality.
  • Vented or Unvented: A vented crawl space opens to the outside, while an unvented crawl space is completely sealed. Vented spaces may cost more if additional sealing of the area is required.

Types Of Crawl Space Insulation

There are several types of crawl space insulation, and the material you choose may depend on the placement of your crawl space and your budget. Common choices for both attic and basement crawl spaces include:

  • Fiberglass Batt Insulation: Wide availability and low cost make fiberglass one of the most popular choices for crawl space insulation. While its flexibility makes it relatively easy to use, it can absorb moisture and sag or fall out of place, which may deter some from choosing this type of insulation.
  • Foam Board Insulation: A material similar to Styrofoam, foam insulation has a rigid design that can be cut to fit any area of the crawl space. It is especially effective at preventing heat transfer, and it also deters water and moisture. It is relatively inexpensive, however its design is challenging to use in smaller nooks and crannies, which means it could be ineffective for certain crawl spaces.
  • Spray Foam Insulation: Spray foam insulation is an organic compound that is flexible enough to fit in any space before it hardens. It is one of the best options for crawl space insulation, because it is water resistant, seals all cracks and holes, and is durable. It also does not sustain mold growth and has no attraction for pests. These advantages do mean that it is one of the most expensive forms of insulation available.
  • Blown-In Insulation: Blown-in insulation is particularly good for the attic crawl space since you don't need to physically enter the space to apply it. Instead, it is blown from below with a hose. This insulation is effective at filling all the tight gaps.

Significance Of Crawl Space Insulation

Significance Of Crawl Space Insulation

If you notice your floors are noisy, always cold to the touch, or you have skyrocketing energy bills and you can't figure out why, insulating the crawl space could solve your problems. When the crawl space is un-insulated, it lets heat and cold air seep into an otherwise secure home. In addition, if you live in a warm or humid climate and you don't have a sealed crawl space, then humidity in the crawl space can condense and cause damage to your walls or floorboards. Crawl spaces are often prime spots for moisture and mold growth. Properly installing insulation can protect this open space, keeping it climate controlled and moisture-free.

Insulation Basics

Insulation comes in several forms, but its primary responsibility is the same: to fill gaps and reduce heat transfer. Insulation is measured with an R-value, with R representing the insulation's heat flow resistance in proportion to its thickness. For example, an inch of fiberglass batt insulation might have an R-value of 3.2, while spray foam could have an R-value of 5.9. A higher R-value represents greater energy efficiency.

R-value is also used to determine whether or not the insulation is suitable for certain climates. Depending on where you live, you need insulation suited to the climate. A professional can easily recommend the right insulation for your home environment.

Some types of insulation, such as fiberglass batt insulation, can be hazardous if not handled correctly. Fiberglass can be harmful if touched or inhaled, which means that proper skin and face protection is imperative. Do-it-yourselfers who attempt this project on their own need to be especially careful when handling certain types of insulation.

How To Install Insulation In A Crawl Space

DIY Or Hire A Pro?

It is possible to do this project yourself, but the task could be tedious, or, as mentioned, hazardous to your health. Plus, if you have excessive moisture or mold in the area or you're removing old insulation, you'll want to leave the job to a professional.

How To Install Insulation In A Crawl Space

Although installing insulation is a job that might be best left to the pros, you may want to try it yourself. The steps vary depending on the type of insulation you use and whether your crawl space is vented or unvented. Follow these general guidelines for insulating a basement crawl space with batt insulation:

  1. Cover the entire floor with polyethylene sheeting and secure this sheeting in place. This ensures that no ground moisture can enter the crawl space.
  2. To insulate a vented crawl space, measure and place the insulation against the sub-floor located above you. Use insulation that has a vapor retarder, and place the vapor retarder facing up towards the room above you. Using batt insulation fit the insulation into the joists against the bottom of the floor. The insulation should fit snugly so there are no air pockets between the floor and the insulation. Secure the insulation in place with insulation supports or chicken wire.
  3. If your crawl space is unvented, place the insulation around the perimeter walls, rather than the floor. Measure the space and cut insulation strips to the appropriate length. Use nails to fasten the insulation to the band joist at the top of the wall, so it hangs down and extends to the floor.

Find A Pro

Hiring a professional to insulate your crawl space is one of the best ways to ensure the job is done safely and completely. If you're ready to implement this change in your home, use our free lead generator to find a local insulation professional today.

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Last updated on Nov 8, 2018

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