Flexible batts insulation placed in floor joists above an unheated crawl space should do what?

Flexible batts insulation placed in floor joists above an unheated crawl space should do what?

• A. Be well supported between joists
• B. Be free-floating
• C. Be compressed tightly
• D. Be stapled to subfloor only

Answer: (A)

Insulation in floor joist cavities must be held in place by the framing so it stays between the joists and fills the cavity. When flexible batt insulation is well supported between the joists, it maintains its rated thermal resistance and stays put, preventing gaps that would let heat transfer occur. If the batt is allowed to be free-floating, it can sag and settle away from the cavity, creating voids. Compressing the batt tightly reduces its R-value and can trap moisture, reducing effectiveness and potentially causing other issues. Sticking insulation to the subfloor only would not keep it properly positioned between the joists, leaving the space inadequately insulated. Therefore, the correct approach is to keep the insulation well supported between the joists.

Insulation in floor joist cavities must be held in place by the framing so it stays between the joists and fills the cavity. When flexible batt insulation is well supported between the joists, it maintains its rated thermal resistance and stays put, preventing gaps that would let heat transfer occur. If the batt is allowed to be free-floating, it can sag and settle away from the cavity, creating voids. Compressing the batt tightly reduces its R-value and can trap moisture, reducing effectiveness and potentially causing other issues. Sticking insulation to the subfloor only would not keep it properly positioned between the joists, leaving the space inadequately insulated. Therefore, the correct approach is to keep the insulation well supported between the joists.