Spec

venting, airbrick, vent, telescopic, periscopic

Visqueen certified with Quality Management System ISO 9001:2015 Visqueen certified with Occupational Health and Safety System ISO 45001:2018 Visqueen certified with Environmental Management System ISO 14001:2015

Visqueen Adjustable Z Vent and Airbrick system is used within external masonry cavity wall constructions to provide a clear airflow passage to the void beneath precast suspended segmental ground floors e.g. beam and block. The system is used to achieve a passive subfloor ventilation system in accordance with BS8485:2015 + A1:2019, effectively diluting any hazardous ground gases accumulating in the underfloor void. The telescopic feature enables the vent to adjust vertically within the cavity to between three and five brick courses (225mm and 375mm). The airbrick replaces individual masonry bricks in the external leaf. The system includes a Visqueen Extension Sleeve which increases the adjustment of the vertical portion of the vent by a further two brick courses (150mm). Additional sleeves can be used to extend the coursing indefinitely. The extension sleeves can also be used to extend the horizontal portion of the vent e.g. for wider cavity applications.

Visqueen Adjustable Z Vents and Airbricks should be stored horizontally, under cover in the original packaging. Care should be taken when handling the product in line with current manual handling regulations.

Visqueen Adjustable Z Vent and Airbrick fit within a 50mm wide cavity, but also suits wider cavities that are filled with insulation leaving only a 50mm gap. A Visqueen Extension Sleeve is necessary to extend the vent horizontally where cavities are in excess of 200mm.

Visqueen Adjustable Z Vents and Airbricks should be installed during the normal course of bricklaying. A Visqueen Zedex CPT High Performance DPC cavity tray should be fitted above the vent. Vents and airbricks should be fitted in at least two opposing walls to create a through flow of air. The vents and airbricks should be placed at centers as stipulated in BS8485:2015 + A1:2019 and within 450mm of each end of the wall. Bricklaying should then be completed as normal although care should be taken to keep the air flow passage clear from mortar droppings. Where the vents require extending, Visqueen Extension Sleeves should be used.

There are no temperature range restrictions for installing Visqueen Adjustable Z Vents, Airbricks and Extension Sleeves.

The system can also be used with a Visqueen Gas Vent Mat dispersal layer. For guidance on this or the required number of units to achieve a passive subfloor ventilation system in accordance with BS8485:2015 + A1:2019, contact Visqueen Technical Services +44 (0) 333 202 6800. The information in this datasheet was correct at the time of publication. It is the user’s responsibility to obtain the latest version of the datasheet as it is updated on a regular basis. The information contained in the latest datasheet supersedes all previously published editions.

Refer to the Visqueen Adjustable Z Vent and Airbrick safety datasheet (SDS).