Cost of insulating crawl space through 2023 | foam spray, plate, blown, block (2023)

Cost of insulating crawl space through 2023 | foam spray, plate, blown, block (1)

Written by

Tara Bauer

Edited by

Kristen Cramer

Checked by

Group Tom

Cost of isolating the crawl space

Cost of isolating crawl spaces1.00 twice $4.50 per square footor500 US-Dollar bis 3.700 US-Dollaron average. Spray foam insulation at the cost of a home$2 to $5 per square foot. Overriding insulation in a crawl space adds1 to 2 dollars per square meterto remove old insulation.

Cost of isolating the crawl space
QuadratfussWall insulation costs*Subfloor insulation cost
700US$ 330 – US$ 1.500700 US-Dollar – 3.150 US-Dollar
1.000US$ 420 – US$ 1.900$ 1.000 - $ 4.500
1.200US$ 450 – US$ 2.000US$ 1.200 – US$ 5.400
1.500US$ 480 – US$ 2.2001.500 $ - 6.800 $
2.000US$ 540 – US$ 2.400$ 2.000 - $ 9.000
2.500600 US-Dollar – 2.700 US-DollarUS$ 2.500 – US$ 11.300

*Based on a 3ft high crawl space

Average cost to insulate a crawl space

The table below shows the average cost of isolating a crawlspace:

Cost of insulating crawl space through 2023 | foam spray, plate, blown, block (2)
Average cost to insulate a crawl space
national average cost1.800 $
Minimal cost320 $
maximum Cost10.000 $
average cost range500 US-Dollar bis 3.700 US-Dollar
(Video) Do not use SPRAY FOAM until you watch this! Our SPRAY FOAM ventilation and humidity nightmare!

*Cost data comes from research and project costs reported by HomeGuide members.

Cost of installing insulation under the house by type

Installation of insulation under the cost of a house500 US-Dollar bis 3.700 US-Dollar, depending on the type and location.

  • Insulation of the subfloor and beams from the edge is best in ventilated rooms.

  • The insulation of the walls and beams from the frame is ideal in closed and unventilated areas.

  • In cold climates, it is recommended to insulate the subfloor, walls, and framing joists.

Cost of installing insulation under the house by type
type of insulationlocation of the tracking roomcost per square metertotal installation costs*
Closed cell spray foam insulationwalls + subfloorUS$ 2,00 – US$ 5,00850 US-Dollar – 6.700 US-Dollar
foam boardparedesUS$ 1,20 – US$ 3,70500 US-Dollar – 1.600 US-Dollar
foam boardunderbodyUS$ 1,20 – US$ 3,701.200 US-Dollar – 3.700 US-Dollar
blownunderbodyUS$ 1,00 – US$ 2,80$ 1.000 - $ 2.800
Roll and fleece (glass fiber, rock wool)underbodyUS$ 0,90 – US$ 1,40900 US-Dollar – 1.400 US-Dollar

* Average total for a 1000 SF crawl space with 3 foot walls.

  • Rigid foam boards can be expanded polystyrene (EPS), extruded polystyrene (XPS) or polyisocyanurate (polyiso, ISO).

  • Insulation for rolls and blankets can be fiberglass, rock wool, natural fibers or plastic. Roll and Batt is best reserved for subfloors in dry, air-conditioned spaces.

  • Fiberglass insulation is the most common, but it is the most problematic in ventilated spaces. Fiberglass will loosen over time and also absorb moisture, reducing its insulating value and potentially causing mold and structural damage.

  • Blown insulation is not typically recommended for crawl spaces, but can be useful for other insulation in very confined spaces.

Cost of insulating crawl space through 2023 | foam spray, plate, blown, block (3)

Spray foam insulation for crawl space costs

Cost of spray foam insulation$2 to $5 per square footto a crawl space. Spray foam insulation under a house works best in combination with rigid foam board insulation. Closed Cell Spray Foam is ideal for sealing subfloor joints and for insulating and sealing floor joists.

Pros and cons of closed cell spray foam insulation
AdvantagesIn contrast
  • Continuous
  • Does not lose its R-value over time
  • Creates a moisture barrier
  • Provides an airtight seal
  • Adds strength to foundations
  • Inert material - no food source for bacteria, mold or mildew
  • More expensive than fiberglass
  • Requires professional installation
  • Difficult to remove if necessary for future repairs
  • may trap moisture
  • May shrink over time in areas with extreme temperature differences
  • Needs time to heal

Closed cell foam is preferred for crawl spaces because it has a higher R-value per inch and offers a moisture barrier. Open-cell foam allows moisture to penetrate and is best for above-ground applications.

(Video) Yep… This is my house.. and this is me fixing MY mistake

Crawl Space Isolation Cost Calculator

Crawl Space Isolation Cost Calculator
Factorcost per square meter
insulating materialsUS$ 0,50 – US$ 3,20
installation workUS$ 0,50 – US$ 1,30
Total cost of installationUS$ 1,00 – US$ 4,50

The following factors affect the costs:

  • area size– Square footage and wall height affect the amount of material and labor involved.

  • Accessibility– Ease of access affects labor costs. Jobs in hard-to-reach areas usually take longer.

  • type of insulation Roll-and-batt insulation is cheaper than rigid foam board. Spray foam is the most expensive.

  • With Face vs. No Face– Costs for insulation batting compared$0.10 to $0.25 per additional square footas uncoated insulation and includes a vapor barrier.

  • Geographical location– Homes in climates with extreme temperature fluctuations require thicker insulation, which costs more.

  • Ventilated space vs. unventilated– Insulating a ventilated crawl space may require additional waterproofing to meet current building codes.

  • remove old insulation– Removal and disposal of old insulation costs$0.75 to $2.00 per square foot.

  • Preparation– Spray foam requires a clean, dry surface. Cleaning and preparation can increase the working time.

Get free quotes from insulation contractors near you.

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Cost of insulating crawl space walls compared to the ground floor of the house

Crawl space wall insulation costUS$ 420 bis US$ 1.900for a 1,000 square foot room with 3 foot high walls. Insulation of the basement of the house costs with the same space requirement1.000 US-Dollar bis 4.500 US-Dollar.

  • Insulate the subfloor and frame joists if the span is ventilated.

  • Insulate walls and edge joists if the crawl space is unventilated or contains HVAC ducts.

Crawl Space Isolation Pricing by R-Value

The R-value is a measure of a material's thermal resistance. The higher the R-value, the better the insulator. The recommended R-value for a crawl space depends on the climate and local building codes.

Crawl Space Isolation Pricing by R-Value
bravery rfoam boardClosed cell spray foamroll and bata
R-6 and R-7$ 1,00 - $ 1,80$ 1,50 - $ 2,50US$ 0,70 – US$ 1,00
R-12 and R-14$ 1,50 - $ 2,50US$ 2,00 – US$ 3,80US$ 0,90 – US$ 1,20
R-18 and R-21US$ 2,20 – US$ 4,00US$ 3,00 – US$ 4,50$ 1,00 - $ 1,30
R-22 and R-30US$ 2,80 – US$ 4,60US$ 4,00 – US$ 5,50$ 1,10 - $ 1,50

*All prices are per square meter installed.

(Video) Crawl Space Insulation! What Kind Is Best?

Cost of insulating crawl space through 2023 | foam spray, plate, blown, block (4)

Labor costs for installing the crawl space insulation

ÖLabor costs for installing insulationis in a crawl space$0.50 to $1.30 per square foot, depending on the type of insulation. Batting is installed quickly. Spray foam takes more prep time, but is quicker to apply than foam sheet, which requires trimming, trimming, and sealing each piece.

Crawl space cleaning and repair

Crawl space cleaning and repair costs500 US-Dollar bis 8.000 US-Dollar, depending on the condition. Repairs can include vent and foundation repairs, mold removal, pest control, and more. Cleaning and repairing the room is essential to ensure the new insulation isn't masking underlying issues that can worsen over time.

Trace or containment room vapor barrier

Track space encapsulation costs3.000 US-Dollar bis 8.000 US-Dollarand is recommended for homes in areas with high humidity. Installing a vapor barrier costs $1.200 bis 4.000 $. If you are using uncoated fiberglass insulation, the crawlspace is first coated with a vapor barrier to add a moisture control layer.

DIY Cost to Isolate a Crawl Space

The DIY cost to insulate a crawlspace is150 US-Dollar bis 700 US-Dollar. It is recommended that a professional be hired to ensure there is no water damage or pest issues, that all gaps are sealed and that the new insulation is installed correctly.

Effective insulation of a crawl space includes:

  • Get rid of all water sources

  • Remove old insulation

  • With mildew resistant and waterproof insulation

  • Insulate the walls instead of the ceiling

  • Sealing of all openings, crevices and hatches

  • Seal edge joists with boards or closed cell spray foam

  • Installing a vapor barrier in the floor

  • Remove accumulated moisture with a dehumidifier once installation is complete

Frequently asked questions about crawl space isolation

Should a crawl space be insulated?

Yes, a crawlspace must be isolated. Uninsulated crawl spaces are a common source of unconditioned air entering the home. Cold floors, high utility bills, and frozen or burst pipes are all signs that the home needs better crawl space insulation.

What are the benefits of isolating a crawlspace?

The benefits of insulating a crawl space include:

  • Prevents cold floors and drafts at skirting boards

  • Improves indoor air quality and comfort

  • reduce energy costs

  • Keeps out pests and rodents (closed cell spray foam)

  • Adds a moisture barrier (closed cell spray foam)

  • Avoid frozen hoses

What R-value for crawl space floor insulation?

The recommended R-value for crawl space floor insulation isR-13 and R-30, depending on the geographical location of the house. The colder the climate, the higher the recommended R-value.

What is the best type of insulation for a crawl space?

The best type of crawl space insulation is a combination of rigid foam and closed cell spray foam. Both types provide insulation and an air and moisture barrier when properly sealed. The best place to put the insulation depends on accessibility and whether the room is ventilated or not.

  • ventilated– Insulate the subfloor or ceiling of the crawl space with rigid foam. Seal gaps in the subfloor and edge joists with spray foam and insulate ducts and pipes before installing the underbody insulation.

  • not ventilated– Use sealed rigid foam on the walls of the crawl space. Use spray foam to seal and insulate the beam from the rim. Underbody insulation is also recommended in cold climates.

    (Video) How To | Total Crawl Space Encapsulation | Step-By-Step | My DIY Center

Can you use spray foam insulation in a crawl space?

Spray foam insulation can be used in a crawl space. Still, many experts do not recommend using it as sole insulation because it makes future floor repairs more difficult to access.

Do you still have doubts? Ask a professional.

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Tips for hiring an insulation contractor

BeforeHire an insulatorHow to isolate your crawl space:

  • Get at least three estimates to compare.

  • Look for professionals with experience in isolating crawlspaces.

  • Read their reviews on HomeGuide and Google.

  • Select companies that are insured, bonded and have been in business for over 5 years.

  • Ask for references.

  • Avoid picking the lowest bid as quality may suffer.

  • Receive a detailed estimate, contract and written guarantee before you start work.

  • Never pay in full before the project begins. Use a compensation plan for completed work.

Questions that need to be asked

  • Are you licensed, bonded and insured?

  • How long have you been in business?

  • What are your experiences with crawl space insulation?

  • What type of insulation do you recommend for my crawl space and why?

  • What is included in the estimate and what is not?

  • What additional costs should I expect?

  • How long does the installation take?

  • How long should the isolation last?

    (Video) learn how to insulate old crawlspace walls with a froth pack 200 unboxing keep snakes mice out

  • Is there a guarantee and if so what does it include?

  • Are there discounts and do you request them?


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