What is the minimum height that unfaced fiberglass batt insulation must fill the entire cross section of a wall cavity?

The minimum height that unfaced fiberglass batt insulation must fill to adequately fill the entire cross section of a wall cavity is 16 inches. This requirement ensures that the insulation performs effectively at reducing thermal bridging and minimizing energy loss in the structure.

Fiberglass batt insulation is designed to fit snugly within standard wall cavities, which typically have an insulation depth of 16 inches for stud spacing. When the insulation does not meet this minimum height, there can be gaps or voids that significantly decrease its effectiveness, allowing for potential air infiltration and thermal loss. Therefore, maintaining this minimum height is crucial for ensuring that the insulation achieves its intended R-value and energy efficiency in residential and commercial buildings.