Glidevale RV Rafter Ventilators are designed for use with FV Fascia Ventilators and SV Soffit Ventilators to ensure a clear air path between the roof underlay and insulation at all types of eaves. Suitable for new build and refurbishment work.Laid continuously over the rafters before the underlay is fixed, provides a maximum 25 000mm2 dependent on eaves ventilation inlet provision. Universal, adjusts for 400 - 600mm rafter centres.Available in 4 widths: 300mm, 450mm, 600mm and 900mm.Suitable for 10,000mm2 per metre or 25,000mm2 per metre continuous eaves ventilation.Quick to install in handy 6m rolls (2x 6m rolls per pack).CoverageEffective coverage per length for rafter spacings:900mm - 6.0m or 7 rafter voids.600mm - 6.0m or 10 rafter voids.450mm - 6.0m or 13 rafter voids.400mm - 6.0m or 15 rafter voids.Please note there are 2x 6m rolls per pack so effective coverage would be double the amount stated per pack.ApplicationRV Rafter Ventilators are designed to ensure a clear air path between roof underlay and insulation at all types of eaves, in accordance with Building Regulations Approved Document C2. They should be installed continuously with FV Fascia Ventilators or SV Soffit Ventilators, to provide a continuous ventilation path from the roof void to the outside without impairing the weatherproof function of the structure, as required by BS 5250.