Combination insulation stop and ventilation baffle

Claim 1

A combination insulation stop and ventilation baffle for mounting over an exterior wall and between a roof and ceiling of a building structure to provide a ventilation passageway to an air space between the ceiling and the roof and to prevent insulation which is subsequently applied to the ceiling from clogging said passageway, in which the exterior wall has a bearing plate on which ceiling joists and inclined parallel roof rafters are supported, said rafters being spaced from each other a first predetermined distance and said roof and bearing plate spaced from each other a second predetermined distance, said combination insulation stop and ventilation baffle comprising: a body of stiff sheet material having (1) a length dimension between end edges greater than the second predetermined distance, and (2) a width dimension between side edges greater than the first predetermined distance; said body having parallel side fold lines formed therein adjacent and spaced from the side edges defining side sections between the side fold lines and the side edges and a central section between the parallel side folds, in which the distance across the central section between the side fold lines is slightly less than the first predetermined distance to enable the side sections to be pivoted in the same direction relative to the central section and the body inserted between two rafters over the exterior wall at an inclined angle to the ceiling joist with the side section bearing against the rafters and one end edge engaging the bearing plate, the other end edge projecting into the air space to define a ventialtion passageway between roof rafters to the crawl space; said body being scissile along said side fold lines, enabling slots to be formed therein extending inward from the other end edge with the distance between the slots being less than the first predetermined distance; and said body having an end fold line formed therein extending perpendicular between the side fold lines forming a flexible end tab which may be freely pivoted about the end fold line upward between the rafters relative to the central section to block one end of the ventilation passageway and prevent insulating material from passing into the ventilation passageway as the insulation is applied between the ceiling joists and which may be subsequently pivoted downward in the other pivot direction relative to the body central section to open said end of the ventilation passageway to permit a flow of air therethrough to the crawl space after the insulation has been applied between the ceiling joist.