INSTALL GUIDES: Crawl Space

Use: Prodex 48 Inch, 10 M, 72 Inch, 24 Inch or 16 Inch or Prodex Under Concrete


How To Insulate A Crawl Space

Installing on Crawl Space Ceiling (3 methods)

A: Staple or screw 10M, Prodex 48 Inch or Fast Action under floor joist. Tape seams with reflective tape (Fast Action and 10M don't require seam tape).

B: Depending on joist spacing, staple, or screw  Prodex 16 Inch or 24 Inch between joists 2" to 4" below floor board. Tape seams with reflective tape.

3: Combine method A and B to maximize performance.

Installing on Wall of Crawlspace: Use glue (super metal sealant) and double sided tape to attach Prodex to concrete wall.

Floor: Roll out Prodex Total Under Concrete on crawlspace floor - White side down facing dirt. Overlap insulation by 3 inches and tape seams with reflective tape.

Benefits of Prodex Total Insulation In Crawlspace

  1. Keep your floors noticeably warmer
  2. Reduce air infiltration and drafts
  3. Save energy and money by keeping heat and air conditioning inside
  4. Minimize problems with condensation, wood rot, mold and mildew
  5. Provide waterproofing
  6. Seal entry paths against termites
  7. Radon resistance


Crawl Space Insulation - Moisture and Cold Are Primary Considerations


  • Problems Caused by Moisture
  • Challenges To Insulating a Crawl Space
  • Components of the Best Crawl space Insulation
  • Crawl space Insulation Options
  • Installing Crawl space Insulation
  • Why Buy Here
  • Crawl space Insulation For Sale
  • Pricing and Buying Crawl space Insulation 

Due to the underground environment, moisture and cold are the primary considerations in developing a crawl space insulation strategy. Excess moisture can cause mold, mildew, odors, decay, fungus growth and wood rot. Cold temperatures below will increase your energy costs and make it less comfortable to walk on your floor.


The underground environment of a crawl space presents unique challenges. The moisture content in soil below three feet deep is almost always higher than the moisture content of the air inside. This difference in vapor pressure causes moisture to be driven from the soil into the crawl space interior by diffusion through the wall. A significant amount of moisture from the soil below the slab will wick upward into the crawl space. Prodex Total, vapor barrier crawl space insulation, solves your moisture and thermal protection needs.


Challenges To Insulating A Crawl Space:


  • The Soil below your home
  • Hydrostatic pressure against the foundation wall from rainfall, snow melt or irrigation creates exterior diffusion
  • Air infiltration bringing moisture in.
  • Groundwater leakage through the foundation
  • Interior diffusion from humidity in warm indoor air
  • Condensation formed due to temperature differences between ground and wall

Underground soil temperatures can be much colder than either the outside air or the indoor air. The warmer the air of the basement constantly expands. When this warm air reaches the cooler surface of a wall next to the ground, condensation will occur on the interior of the wall. Any insulation in your crawl space will be subject to potentially large amounts of moisture driven from both the exterior and the interior depending on the season.


Air infiltration can be a major source of moisture entering your crawl space. A lot more water vapor can move through a very small opening where the vapor pressure is greater on the exterior than can move through the wall surface by diffusion. Air-transported moisture can quickly lead to mold, mildew and decay in interior wall assemblies. Properly insulating a crawl space requires addressing all these challenges.


fiberglass insulation in crawl space

Fiberglass insulation should not be used in a crawl space! To maintain its thermal effectiveness, fiberglass insulation cannot be exposed to moisture. Moisture will degrade the insulation R-value of fiberglass batts and promote mold and mildew. Installing a vapor barrier over the interior of fiberglass insulation will not prevent the foundation walls from drying to the interior, migrating capillary rise and ground water leakage. Batts with no vapor barrier will not be effective either as

interior humidity will still cause loss of insulation R-value. U. S. Department of Energy: The R-value of some insulations also depends on...moisture accumulation.

R-value test parameters

crawlspace prodex total insulation

Prodex Total crawlspace insulation does not support mold, mild or fungus growth. It does not lose thermal effectiveness when wet. 

Your home can act like a vacuum drawing radon up through the crawlspace in two ways. First, the air pressure inside is usually lower than pressure in the soil around the foundation. Second, warm air will rise to leak out creating a small amount of suction that can pull radon gas up through the crawlspace. A poorly

insulated crawlspace can account for 15 percent or more of a building's total heat loss. Prodex is most effective against downward radiant heat transfer making it a builder's choice for crawlspaces as a radiant barrier. Heat radiating downward from your floor into the crawlspace will be reflected back inside, saving energy and maintaining constant room temperatures. The most recent advance in crawlspace insulation is Prodex Total as a vapor barrier, radon barrier and insulation combined in one product.

Components Of The Best Crawl Space Insulation


  • Keep your floors noticeably warmer
  • Reduce air infiltration and drafts
  • Save energy and money by keeping heat and air conditioning inside
  • Minimize problems with condensation, wood rot, mold and mildew
  • Provide waterproofing
  • Seal entry paths against termites
  • Control radon infiltration

Independent reviews ar the Better Business Bureau and Site Jabber

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