Insulating roofing element - has waterproof sheet fixed with narrow lateral and long longitudinal overlap to foam plastic cut for rolling

摘要

The insulating roofing element consists of a layer of foam plastic or the like with a sheet of flexible waterproof material secured to one surface. The foam plastic is provided with cuts in its other surface to permit winding the element into a roll. The sheet projects laterally beyond the foam layer by a small amt. to provide an overlap at the join between adjoining elements. It also projects in longitudinal direction by an amt. at least equal to the length of the foam layer to overlap a longitudinally adjoining element thus providing a double sheet covering when laid. The length of the longitudinal overlap is pref. equal to the length of the foam layer plus the width of the lateral overlap.