Written by
Tara Bauer
Edited by
Kristen Cramer
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Crawlspace Isolation Cost
Crawlspace Isolation Cost1.00 twice $4.50 per square footo500 bis 3,700 US dollarsaverage. Spray Foam Insulation Low House Costs$2 to $5 per square foot. Replacing insulation in a crawl space adds$1 to $2 per square footto remove old insulation.
| Quadratfuss | Wall insulation costs* | subfloor insulation cost |
|---|---|---|
| 700 | $330 – $1.500 | $700 – $3.150 |
| 1.000 | $420 – $1.900 | 1.000 $ – 4.500 $ |
| 1.200 | $450 – $2.000 | 1.200 $ – 5.400 $ |
| 1.500 | $480 – $2.200 | 1.500 $ – 6.800 $ |
| 2.000 | $540 – $2.400 | $2.000 – $9.000 |
| 2.500 | $600 – $2.700 | $2.500 – $11.300 |
*Based on a 3 foot high crawl space
Average cost to insulate a basement
The following table shows the average cost to insulate a basement:
| National Average Cost | 1.800 $ |
| Minimal cost | $320 |
| maximum cost | 10.000 $ |
| average cost range | 500 bis 3,700 US dollars |
*Cost data comes from research and project costs reported by HomeGuide members.
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Cost of installing insulation under the house by type.
Installing insulation below a house costs.500 bis 3,700 US dollarsdepending on the type and location.
Insulation of the subfloor and edge joists is best in ventilated rooms.
Insulation of walls and edge joists is ideal in enclosed, non-ventilated areas.
In cold climates, it is recommended to insulate the subfloor, walls, and rim joists.
| insulation type | Crawl space location | cost per square meter | Total installed cost* |
|---|---|---|---|
| Closed Cell Spray Foam Insulation | walls + basement | $2,00 – $5,00 | $850 – $6.700 |
| foam board | paredes | 1,20 $ – 3,70 $ | $500 – $1.600 |
| foam board | underbody | 1,20 $ – 3,70 $ | 1.200 $ – 3.700 $ |
| blown in | underbody | 1,00 $ – 2,80 $ | 1.000 $ – 2.800 $ |
| Roll and fleece (fiberglass, rock wool) | underbody | 0,90 $ – 1,40 $ | $900 – $1.400 |
* Average total for a 1,000 square foot crawl space with 3 foot walls.
Rigid foam boards can be made of expanded polystyrene (EPS), extruded polystyrene (XPS) or polyisocyanurate (polyiso, ISO).
Roll and batt insulation 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 most problematic in ventilated crawl spaces. Fiberglass degrades over time and also absorbs moisture, which reduces its insulating value and can cause mold and structural damage.
Blow-in insulation is generally not recommended for crawl spaces, but it can be useful in spaces that are too tight for other types of insulation.
Spray foam insulation for crawl space costs
Spray Foam Insulation Cost$2 to $5 per square footfor a crawlspace. Spray foam insulation under a home 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.
| Advantages | Disadvantages |
|---|---|
|
|
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 suited for high end applications.
Crawl Space Insulation Cost Calculator
| Factor | cost per square meter |
|---|---|
| Insulating materials | 0,50 $ – 3,20 $ |
| installation work | 0,50 $ – 1,30 $ |
| Total cost of installation | 1,00 $ – 4,50 $ |
The following factors affect costs:
area size– The number of square meters and the height of the wall influence the material and labor costs.
Accessibility– Ease of access affects labor costs. Jobs in hard-to-reach areas often take longer.
insulation type– Roll and batt insulation is less expensive than rigid foam board. Spray foam is the most expensive.
Confronted vs Not Confronted– Comparison of the costs of insulation cotton$0.10 to $0.25 more per square footas unfaced insulation and contains a vapor barrier.
Geographical position– Homes in climates with extreme temperature fluctuations require thicker insulation, which costs more.
Ventilated space versus non-ventilated space– Insulation of a ventilated basement may require additional waterproofing to meet current building codes.
Removal of old insulation.– Cost of removing and disposing of old insulation$0.75 to $2.00 per square foot.
Preparation– Spray foam requires a clean, dry surface. Cleaning and preparation can increase work time.
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Cost of insulating basement walls from the bottom of the house floor
Crawl Space Wall Insulation Cost420 bis 1,900 US dollarfor a 1000 square foot room with 3 foot high walls. Insulation of the lower floor of the house costs with the same space requirement1,000 bis 4,500 US dollars.
Insulate subfloor and edge joists if crawl space is ventilated.
Insulate walls and edge joists if crawl space is unventilated or contains HVAC ductwork.
Crawlspace Isolation Prices by R-Value
The R-value is a measure of a material's resistance to heat. 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.
| valor R | foam board | Closed Cell Spray Foam | roll and bat |
|---|---|---|---|
| R-6 a R-7 | 1,00 $ – 1,80 $ | 1,50 $ – 2,50 $ | 0,70 $ – 1,00 $ |
| R-12 a R-14 | 1,50 $ – 2,50 $ | $2,00 – $3,80 | 0,90 $ – 1,20 $ |
| R-18 a R-21 | $2,20 – $4,00 | $3,00 – $4,50 | 1,00 $ – 1,30 $ |
| R-22 a R-30 | $2,80 – $4,60 | $4,00 – $5,50 | 1,10 $ – 1,50 $ |
*All prices are per installed square meter.
Labor costs to install crawl space insulation
HeLabor costs to install the insulation.is in a crawl space$0.50 to $1.30 per square footdepending on the type of insulation. The batting sets up quickly. Spray foam requires more prep time, but is quicker to apply than sheet foam, which requires trimming, trimming, and sealing each piece.
Basement cleaning and repair
Crawl space cleanup and repair costs$ 500 a $ 8,000, depending on the condition. Repairs can include vent and foundation repairs, mold remediation, pest control, and more. Cleaning and repairing the room is essential to ensure that the new insulation does not hide any underlying problems that could worsen over time.
Vapor barrier or crawl space containment
Cost of encapsulating crawlspaces3,000 to 8,000 US dollarsand is recommended for homes in areas of high humidity. Installing a vapor barrier costs $1.200 a 4.000 $. If you are using bare fiberglass insulation, the crawl space is first covered with a vapor barrier to add a layer of moisture control.
DIY Cost to Insulate a Crawl Space
DIY cost to insulate a crawl space is$150 a $700. Hiring a professional is recommended to ensure there are no water damage or pest issues, all gaps are sealed, and new insulation is installed properly.
Effective crawl space insulation includes:
Get rid of all sources of water.
remove old insulation
With waterproof and mold resistant insulation
Insulation of the walls instead of the ceiling.
Sealing of all vents, gaps and hatches
Seal edge joists with boards or closed-cell spray foam
Installation of a vapor barrier in the ground.
Remove accumulated moisture with a dehumidifier once installation is complete
Basement Insulation FAQs
Should a basement be insulated?
Yes, a crawl space must be isolated. Uninsulated crawl spaces are a common source of unconditioned air entering the home. Cold floors, high energy bills, and frozen or burst pipes are all signs that your home needs better crawl space insulation.
What are the benefits of insulating a basement?
The benefits of insulating a basement include:
Avoid cold floors and drafts along skirting boards
Improves indoor air quality and comfort.
Reduce energy costs
Prevents entry of pests and rodents (closed cell spray foam)
Adds a moisture barrier (closed cell spray foam)
Prevent frozen pipes
What R-value for crawl space floor insulation?
The recommended R-value for crawl space floor insulation isR-13 a R-30, depending on the geographical location of the house. The colder the weather, the higher the recommended R-value.
What is the best type of insulation for a basement?
The best type of crawl space insulation is a combination of rigid foam and closed-cell spray foam. Both types provide insulation and a barrier against air and moisture when properly sealed. The best place to apply the insulation depends on accessibility and whether or not the space is ventilated.
ventilated– Insulate the subfloor or basement ceiling with rigid foam. Seal gaps in subfloor and edge joists with spray foam and insulate ducts and pipes before installing underbody insulation.
without ventilation– Use sealed rigid foam on crawl space walls. Use spray foam to make a tight seal and insulate the edge joist. In cold climates, underbody insulation is also recommended.
(Video) Foam vs Fiberglass vs Cellulose: Which Insulation is Best for My Home? | Foam University
Can spray foam insulation be used in a crawl space?
Spray foam insulation can be used in a tight space. Still, many experts advise against using it as sole insulation because it makes it difficult to access for future underbody repairs.
Do you have any other questions? Ask a professional.
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Tips for Hiring an Insulation Contractor
BeforeHire an insulation companyHow to isolate your crawl space:
Get at least three estimates to compare.
Look for professionals with experience in basement insulation.
Read their reviews on HomeGuide and Google.
Select companies that are insured and bonded and have been in business for more than 5 years.
Ask for references.
Avoid choosing the lowest bid as quality may suffer.
Get a detailed estimate, contract and warranty in writing before you start work.
Never pay in full before the project begins. Use a full job pay plan instead.
Questions to ask
Are you licensed, bonded and insured?
How long have you been in business?
What is your experience with crawl space insulation?
What kind of insulation do you recommend for my basement and why?
What is included in the budget and what is not?
What additional costs should I expect?
How long does the installation take?
How long should the isolation last?
(Video) Here's the Inexpensive Way to Up Your Home's InsulationIs there a warranty and if so, what does it include?
Are there discounts and do you apply them?