Specification History

If backing or infill is installed, it will not bend, sag, or move once installed, and will adequately support any insulation installed on the surface

For small holes (less than 1/4"):

if using, install backing or infill material at least 1/8" below the surface where sealant is applied

For medium holes (1/4" to 3"):

install backing or infill in or over all holes to be sealed

For large holes (greater than 3"):

install rigid backing or infill in or over all holes to be sealed

Install support material for spans wider than 24", except when air barrier material is rated to span greater distance under load (e.g., wind, insulation)

Support material installed for any walking/working surface (attics or floors) will support the weight of a worker and any insulation applied in the area

Mechanically fasten backing or infill materials sufficient to prevent movement

Prevent excessive sealant movement and support applied loads