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Glidevale AV50 Abutment Ventilation Product Focus

The Glidevale AV50 Abvent has been designed to provide an unobtrusive solution for high level ventilation to roof spaces. It can be used at the top abutment of a pitched lean-to roof, which is especially useful where there is a limited height above the pitch, due to windows. It can also be used in conjunction with traditional ‘lead roll’ ridge details on plain tile and slate roofs.


As an alternative to ridge ventilators (e.g. Protect Fulmetal RediRoll) or slate and tile ventilators, our abutment vent ensures compliance to BS 5250 Control of Condensation in Buildings. The AV50 can only be used on a pitched roof above 20° as it provides 5,000mm²/m airflow; a roof below 15°, or a flat roof, will require 25,000mm²/m at opposing roof edges to comply. Flat roof ventilation can be achieved through soffit or fascia ventilators, for more information about Glidevale soffit and fascia vent collection please click here. For more information regarding BS 5250 requirements, please read our White Paper.


The AV50 is available with either flashing attached or is provided complete with AluFlash – Glidevale Protect’s lead alternative, or normal lead flashing. Where there is a flat tile or slate finish, the AV50 with no flashing is suitable. However, if the roof finish incorporates profiled tiles, a leaded or AluFlash flashing would be required to prevent any water ingress through the bottom edge of the vent.

Where a sloping roof is abutting a wall, a lead flashing will be installed at the abutment. This flashing will be dressed over the top of the AV50 and tucked behind the integral clips to help prevent uplift.

Please note: We recommend following the directions of the Lead Sheet Association in securing cover flashings.

Product specs

The extruded sections are supplied in 1m lengths. If this length is not suitable, the AV50 can be easily cut with a saw or sharp knife. Leaded and AluFlash versions overlap the next vent to ensure integrity of the flashing.

The AV50 is manufactured from ABS. All exposed surfaces are treated with a UV polymeric resin to ensure the product will endure the elements for the same length of time as the roof.

The ventilator has a 4mm slotted face that will prevent the ingress of nesting insects.

Top tip before installing

Ensure that a suitable air gap and supporting batten for the AV50 is present between the top course of tiles and wall. Depending on the tile type, additional packing may be required to support and fix the AV50 to.

Where to purchase the AV50 Abvent

The unleaded AV50 is available from the BPD Store or can be ordered through most major merchants. For large orders, please contact our Sales team on 0161 905 5700 or

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Glidevale Protect is a division of Building Product Design Ltd.

Other subsidiaries include ventilation systems specialist Passivent and Kingfisher Louvres, manufacturer of aluminium louvres systems.

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