Roof coverings: Puncture, cumulative load (NT BUILD 336)

Abstract

1. SCOPE

This NORDTEST method specifies a test for puncturing under cumulative load. Mechanical stress on roofing varies from static long-term loads to dynamic short-term loads. This method represents an intermediate (semi-dynamic) load category. For puncture by impact see NORDTEST method NT BUILD 335 “Roof coverings: Puncture by impact”.

2. FIELD OF APPLICATION

This method is intended to test resistance to puncture for roofing materials resting on a relatively soft underlay such as polystyrene or mineral wool. But it can also be used for testing the membrane itself, fixed between metal rings.