Crawl Space Insulation Installation Costs and Values

crawl-space-insulationThis guide covers crawlspace insulation purposes and types as well as crawlspace insulation costs. A crawl space is part of a home’s foundation with very little height – hence a crawl space or crawlspace. It may or may not be heated, ventilated or have a poured floor.

Jump to: Insulation Levels | Types | Costs

Reasons to Insulate the Crawl Space

There are two primary reasons to insulate the crawlspace – to add a moisture barrier and to reduce energy use in heating the home.

A moisture barrier is essential to keeping humidity levels down. Excess humidity that transfers through the foundation walls or floor may cause mold in areas such as the ductwork or walls and can lead to rotting of framing timbers. A moisture barrier is very important in non-ventilated crawl spaces.

Insulating the walls of a non-ventilated crawlspace will prevent the loss of heat through foundation walls. If the crawlspace is vented, then insulation should be applied to the ceiling of the crawlspace which is also the subfloor of the home’s first floor. Insulating the ceiling/subfloor will prevent the loss of heat in the winter and the heating of the air in the living space above in the summer.

When planning for crawl space insulation, consider insulating all ducts and pipes that pass through the area. This is essential if the crawlspace is unheated.

Recommended Insulation Levels for the Crawl Space

The recommended R-value for crawlspaces in all zones of the United States and Canada is R-19. In some very moderate climates like those on the Pacific Coast, R-13 or R-15 may be sufficient. An insulation contractor in your area will be able to give you specific code requirements where you live. However, even where local codes allow less insulation, you can’t go wrong with R-19.

Types of Insulation Used in Crawl Spaces

There are three main types of insulation used in crawlspaces: Batt insulation, spray-in foam insulation and rigid foam insulation.

The batts may be fiberglass (a wool-like material made from molten glass) or rock wool (a wool-like material made from molten rock slag). These batts are affordable and come in a variety of thicknesses to create varying R-values. Seams where batts adjoin should be stuffed with additional insulation or taped to prevent air gaps.

Spray in foam insulation has the advantage of offering outstanding coverage since it goes on wet and then cures into a rigid foam with no seams. Open cell (less efficient but more affordable) and closed cell (more efficient and costlier) are available. It is sprayed using a large time, compressor and a spray hose or wand.

Rigid foam insulation comes in 4×8 boards and is used mostly as wall insulation either on the exterior or interior of the crawlspace. It is an ideal insulation for crawlspaces that are NOT vented. There are several types of rigid insulation with R-values of R-4 to R-8 per inch of thickness.

Non-vented crawlspaces often have a combination of rigid insulation on the walls and either batt or spray foam insulation on the ceiling.

Crawl Space Insulation Costs and Comparisons

These crawl space insulation prices will give you an idea of what to expect when you receive bids from insulating contractors in your area.

Roll and Batt Insulation Costs

Table 1: Prices shown for Roll & Batt Insulation, divided down into Material per Sq. Foot and Labor per Sq. Foot:

Insulation RatingMaterial per Sq. FootLabor per Sq. Foot
R-13$0.30 to $0.40 $0.60 to $0.90
R-19 $0.50 to $0.75$0.60 to $0.95

Spray In Foam Insulation Costs

Table 2: Prices shown for Spray-in Foam Insulation, divided down into Material per Sq. Foot and Labor per Sq. Foot:

Insulation RatingMaterial per Sq. FootLabor per Sq. Foot
R-13$0.90 to $1.60$0.57 to $0.90
R-19 $1.30 to $2.50$0.75 to $1.00

Rigid Foam Insulation Costs

Table 3: Prices shown for Rigid Foam Insulation, divided down into Material per Sq. Foot and Labor per Sq. Foot:

Insulation RatingMaterial per Sq. FootLabor per Sq. Foot
R-13$0.75 to $0.90$0.90 to $1.25
R-19 $1.10 to $1.30$0.90 to $1.30

All types of crawl space insulation require additional supplies and materials such as adhesive, fasteners, tape or tools. Expect these costs to be +/- $50 per 1,000 square feet of insulated space.

You’ll find the lowest crawl space insulation prices and the best contractors in your area when you request at least three written estimates from contractors who are competing for your business.

Helpful Resources:

Get Useful Tips on Home Insulation from the US DOE

Learn More about Crawl Space Insulation from a Contractor