Determining Insulation R-Value

• Before picking the insulation type for a basement ceiling, determine the insulation R-value you need, based on the home's location. A home in the southwestern part of the United States using a heat pump, gas, oil or electric furnace requires R-13 or R-25 insulation in the floor, according to the North American Insulation Manufacturers Association. Other areas of the United States, except the aforementioned and a part of Florida, require R-25 to R-30 underneath the floor of the home, or in the basement's ceiling. The tip of Florida only needs R-13 in the floor.
  
  

Fiberglass Batts

• Fiberglass batts are made for installing inside walls between studs or between joists in ceilings and floors. Installing batts involves purchasing insulation as wide as the span between the floor joists and placing the fiberglass batts in between the joists. Fiberglass batts will stay in place because they are light -- don't compress, bind or stuff the insulation in.
  
  

Fiberglass Rolls

• The distance the ceiling spans may be longer than a wall is high. Because fiberglass batt insulation is made to a length to fit inside a stud wall, a ceiling joist spanning 16 feet would require two insulation batts. Purchasing rolled insulation may be a better option, as it allows for the installation of one continuous piece of insulation cut to fit the span.
  
  

Faced Insulation

• An added measure of moisture protection comes with the option of fiberglass insulation with paper facing. When installing this type of insulation, place the paper facing toward the conditioned space and secure it to the joists with periodic staples from a staple gun. This backing keeps moisture from the basement condensing onto the subfloor above and helps to prevent mold in the basement.
  
  

Other Considerations

• If you leave the insulation exposed, purchase insulation with a fire-retardant for extra protection. When installing the insulation, fiberglass's insulating properties come from the air pockets trapped inside the insulation itself. Binding, compressing or stuffing the insulation in between the joists may compromise these properties. Always install insulation without force, and wear a dust mask and a long-sleeved shirt because insulation fibers irritate the skin. When the job is complete, rinse your body first in cold water to remove the fiberglass fibers before engaging the hot water. Hot water opens the pores and allows the fibers entry into the skin, a most unpleasant experience.