BS EN 14964 is one of the European standards that discuss rigid underlays for discontinuous roofing.
BS EN 14964 specifies the technical requirements for factory-made flat or profiled sheets (wood-based, fibre cement flat sheets or corrugated bituminous sheets or other materials which can be characterised as one of these materials) that are used as underlays in pitched roof constructions with discontinuously laid coverings (e.g., tiles, slates). BS EN 14964 also establishes methods of inspection and testing as well as criteria for evaluation of conformity.
Note: BS EN 14964 does not include rigid underlays which have a stiffening function or a load-bearing function.
BS EN 14964 on rigid underlays for discontinuous roofing is useful for:
Rigid underlays for coverings of pitched roofs (e.g., tiles, slates). They can be laid overlapping, one sheet covering the other (OL) or interlocking, sheets side by side. These underlays have various types and characteristics. Hence, the users need to have a good understanding of these underlays to utilize them appropriately in their projects.
BS EN 14964 introduces you to the terminologies and characteristics of rigid underlays for discontinuous roofing that would be useful for you when you refer to other documents on underlays. This guidance of BS EN 14964 will help you gain clarity on rigid underlays.
Overall, the guidelines of BS EN 14964 help produce better quality underlays.EN 14964:2006