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VENT Ventilated Batten VB20

The VENT Vented Batten is a strong, durable purlin cavity batten that is designed to ensure that unimpeded airflow is guaranteed through the roof cavity of a Skillion Roof design, enabling passive airflow around the entire building envelope.

The VB20 is designed with 4mm evenly spaced openings specifically sized to prohibit large insects gaining access but wide enough to prevent capillary action. The VB20 is easy to install and come with an adhesive underside for ease of temporary fixings to metal or timber purlins.

The VB20 should be used in conjunction with other specified VENT products. Although specifically designed as an easy to fit roof ventilation product, the VB20 can also be used on walls to create vertical or horizontal ventilation flows.

Key Features
  • Free airflow of 18,000mm2 per linear metre
  • Releases hot air from roof voids and eliminates condensation
  • Ensures unimpeded airflow through skillion roof cavities
  • Recommended for any skillion roof
  • New Build or Renovation
  • Easy to install — Manufactured in 1800mm lengths for easy handling
  • Additional fixing screw length is required to accommodate 20mm thickness of the VB20
  • Insect proof — Recommended 4mm vents to prevent ingress of nesting insects
  • Manufactured in recycled plastic for affordability
  • 30 year warranty
Scope of Use

Roof Ventilation Products have been appraised for use as non-structural roof battens and vents for use with pitched and skillion roof construction on buildings within the following scope:

  • the scope limitations of NZBC Acceptable Solution E2/AS1, Paragraph 1.1 with regards to building height and floor plan area; and,
  • with profiled metal roof cladding; and,
  • situated in NZS 3604 Wind Zones up to, and including Extra High.

The VENT Vented Batten (VB20) is designed for use on all skillion roof designs irrespective of the roof cladding. It can be used in all climates and weather conditions.

The VENT Vented Batten will fix to the top of the roof purlins, the upper edge of the fascia and underneath the barge flashing, and is compatible with steel and timber purlins.

  • Residential skillion roofing and commercial buildings
  • Designed to ensure that unimpeded airflow through the roof cavity of a skillion roof design
  • Also designed as a purlin vent to allow airflow throughout roof area
  • New build or renovation
  • VB20 can also be used on walls to create vertical or horizontal ventilation flows 


Limitations on Use

The VENT Vented Batten should be used in conjunction with other VENT products to ensure a complete ventilation system:

  • VENT Over Fascia Vent (G2500N)
  • VENT Ridge Vent (RV10P) for application on purlin

Additional fixing screw length is required to accommodate 20mm thickness of the VB20.

NZS 3604 Wind Zone Extra High suitable
Extra High Wind Zone
Statement of Building Code Compliance

VENTs Passive Roof Ventilation Products comply with the following provisions of the NZ Building Code:

  • B1.3.1, B1.3.2
  • B1.3.3 (a)
  • B1.3.4 (a, b, c, d, e)
  • B2.3.1 (a)
  • B2.3.2 (a)

Evidence: All products are manufactured by Manthorpe Building Products Ltd (UK) who are ISO 9001 accredited by SGS Certificate # GB12/84769, certified since 2011.

In-Service History

Passive Ventilation has been used in Canada, America, the United Kingdom and Europe for almost four decades. By introducing passive ventilation into roofs these countries have significantly reduced internal moisture and prevented what was called 'sick home syndrome'.

More recently in New Zealand, since changes to E3:AS1 1.1.4.b of the New Zealand Building Code in 2014, passive ventilation has become more widely understood and the need to ventilate the uninhabited spaces in a building has been more widely acknowledged. Industry experts BRANZ have endorsed passive ventilation as a necessity in Skillion roof types and have recommended that all roof types are passively ventilated as redundancy to eradicate internal moisture.

The NZMRM is currently revising the Metal Roofing Code of Practice to incorporate ventilation into certain roof design and strongly recommending passive ventilation in all metal roof types.  

Since the amendment of E3:AS1 hundreds of New Zealand buildings have incorporated passive ventilation into building design and application, These buildings include MOE school Reroof projects, residential new build and renovations and commercial projects. 

The VENT Ventilated Batten has been sepcified and installed on many Ministry of Education school re-roof projects throughout New Zealand.

Other Performance Attributes
  • 30 year warranty
  • Insect proof — Recommended 4mm vents to prevent ingress of nesting insects
  • Manufactured in recycled plastic 
BRANZ Appraised
BRANZ Appraised
Data Sheet VB20


Passive Ventilation System: Mono Pitch Cold Roof 15-30°
Passive Ventilation System: Skillion Mono Roof <15°
Passive Ventilation System: Skillion Roof Pitch 15-30°
Independent Appraisal (BRANZ)
Video: Why Is Passive Roof Ventilation Necessary
CAD/PDF Details
Full Set of Roof Drawings


04 Steel Longrun — Skillion Roof

04 Apron AB20 and VB20

05 Steel Longrun — Skillion Roof

05 Ridge Barge AB20 and VB20

06 Steel Longrun — Skillion Roof

06 Ridge RV10P and VB20

10 Deep Trough Longrun — Skillion Roof

10 Ridge RV10DT and VB20

15 Steel Longrun — Any Pitch

15 Eave G2500N and VB20

VENT provide complete passive ventilation systems that ensure healthy homes free from internal moisture and condensation.

Product Enquiries

News from VENT

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