Single skin CEDR24E rooflights providing a class B non-fragile roof assembly within a single skin Ziplok 400 standing seam roof. CEDR24E is a nominally 2.4kg/m2 natural translucent diffusing Filon rooflight sheet that uses a woven glassfibre mat to provide a strong but thin product. When tested in accordance with ACR[M]001:2014, this provides a class B non-fragile rating ensuring safety for roof workers during installation and maintenance workers after the construction phase.