Inefficient Crawl Spaces: Avoid Paying For Energy You Don’t Use With These Tips

By insulating and sealing your crawl space, you can make your home more comfortable and reduce your energy costs. How you go about doing that depends on whether your crawl space is ventilated. In Northern Indiana and Southwest Michigan, older homes typically have ventilated crawl spaces. New houses are often built with unventilated crawl spaces.


Unventilated crawl spaces require that you seal and insulate the foundation walls but not the subfloor. If you’re insulating a crawl space without ventilation, you have several advantages:


  • Less insulation is needed.
  • You don’t have to insulate the piping and ductwork.
  • Air sealing is not as vital between the crawl space and the house.


However, there are also disadvantages to insulating unventilated crawl spaces:

  • The material can be damaged by water or pests.
  • The crawl space must be sealed up very tightly to prevent such damage.
  • There must be an access door to the crawl space from inside the house — unless you want to build an airtight, insulated door in the outside wall.


To insulate a ventilated crawl space, we suggest these steps:

  • Seal all the spaces in the floor over the crawl space to prevent air from leaking up into your house.
  • Use rolled fiberglass to insulate the areas between the floor joists. The insulation should be installed tightly against the subfloor. Be sure to seal the seams between the rolled the fiberglass to prevent wind from getting into the material. Use mechanical fasteners to secure the insulation between the joists.
  • Use house wrap or a vapor barrier to cover the insulation.
  • Install a vapor retarder over the dirt floor of the crawl space. Carefully seal all of the seams of the material. Use sand to create a thin protective layer over the retarder. Do not use crushed gravel as it can put holes in the material.


At Home Comfort Experts, our certified heating and cooling technicians would be glad to answer your questions about improving your crawl space. Contact us anytime.


 Home Comfort services the Mishawaka/South Bend areas of Indiana.