The NHBC advises that roof slates conform with BS EN 12326 and importantly they are accompanied with documentation to support the water absorption, carbonate content and reactive metallic materials tests. (A1, S1 and T1). This is to ensure the finished roof matches the proven pass or fail objectives and standards of BS 680. Without this accompanying commercial documentation (often called ACD’s’), the current BS EN 12326 does not embrace the comparable qualities the NHBC seeks.
When it comes to ventilation within the compliant slated roof surface, the specifier now has a new option: The mandatory levels of air throughput can be provided using a proven but modernised traditional approach manufactured from a proven traditional material. Importantly, as with the roofing slates, documentation is available to confirm the compliant qualities of the material.
The Lead Slate Roof Ventilator (Type LSRV) is used to promote airflow in and out of the roof space, or as a dedicated bathroom or kitchen ventilation outlet. Manufactured from code 4 milled lead to BS EN 12588, externally its appearance is traditional. The use of natural lead means it is long lasting whilst benefitting the accompanying ability to sympathetically weather with the roof covering.
The Type LSRV sits comfortably with all slate sizes and requires minimal work to incorporate within slate runs. Natural lead tempers into slate undulations so the Type LSRV accommodates variations that alternative materials cannot.
The airflow aperture incorporates a stainless grille to diffuse wind impact and minimise water entry. Within the ventilator body, the spigot connection rises to function as an elevated outlet and water-check dam against rain ingress. The spigot also projects downwardly into the roof space to service roof space air evacuation. A flexible hose may be connected for specific room extraction. (90mm, 110mm or 150mm). The Type LSRV is supplied with a base size to match the slate dimensions. As the base size increases so does the maximum possible airflow from 3000mm to 8000mm sq².
The Type LSRV is for use in new slate roofs and existing roofs requiring upgrading. When a property is a Listed building or within a Conservation Area, there are strict laws guarding construction and craftsmanship. The Type LSRV may be considered for use on such buildings where an enduring roofing material that has been used since Roman times is aesthetically and sympathetically the preferred medium.