MemTech’s Void Vent 25 offers a passive venting solution which facilitates the dispersal and dilution of dangerous gases. It has been designed to provide for high levels of air and / or gas flow.

MemTech Void Vent is a cuspated HDPE core with a geotextile filter / separator bonded to a single side, in either 25 or 40mm depth.

MemTech Void Vent provides a means of ventilation when used in conjunction with an approved gas protection barrier, in accordance with the recommendation(s) contained within NHBC Guidance and BS8485:2015.

Key features

  • Provides protection against dangerous gases and chemicals

  • Optimised for maximum strength and performance

  • Independently tested and verified by UKAS accredited bodies

  • BBA-certified

  • Complies with the latest codes of practice (BRE, CIRIA and NHBC)

  • Lightweight and easy to install

  • High gas flow capacity

  • Suitable for new and existing structures

  • High resistance to puncture

MemTech Void Vent 25 provides a passive means of ventilation for ground gas protection when used in conjunction with:

  • MemTech Liquid Gas Barrier ‘LGB’

  • MemTech M1

  • MemTech R1

  • MemTech Titon

Product Details

  • Product Code: DMS 404

  • Material: High Density Polyethylene

  • Roll Width: 0.9m

  • Roll Length: 50m

  • Gross roll weight: 60kg

  • CBR Puncture Resistance: kN 1.4 (-0.14)

  • Tensile Strength (MD/CMD): kN/m 20/15 (-2.0/-1.5)

  • Compressive Strength: kPa 300

  • Pore Size (O90) [geotextile]: µm 80 (±20)

  • Water Flow Capacity [Composite] (200kPa, (i) =1): l/m/s 5

  • Gas Flow Capacity [Composite]: m3/s 0.024

Application

MemTech Void Vent 25 is installed underneath a MemTech gas membrane to provide passive ventilation of ground gas in accordance with BS 8485:2015 and creates a de-pressurisation zone for collection of ground gases.

It is either laid to the entire footprint or in 450 or 900mm wide strips at designated intervals to provide appropriate levels of venting depending on CS level, Building type and building width. The MemTech Void Vent is linked to MemTech Vent boxes which provide the link to external atmosphere. These are installed on opposing sides of the building and each vent box provides 18000mm2 ventilation area.