Description

Verificaiton Method E2/VM2 - Cladding systems for buildings up to 25 m in height – including junctions with windows, door and other penetrations.

Verificaiton Method E2/VM2 is a means of testing and demonstrating that a wall cladding system will prevent the penetration of water to the extent required by clause E2.3.2 of the Building Code.

Users of E2/VM2 will also need to identify how the building work addresses the following requirements of clause E2:

• for roof cladding systems, including requirements for shedding water (E2.3.1) and water penetration (E2.3.2).
• to address moisture absorbed or transmitted due to ground contact or proximity (E2.3.3).
• to address the effects of moisture in subfloor spaces (E2.3.4).
• to prevent moisture problems in concealed spaces (E2.3.5).
• to address construction moisture (E2.3.6).

Scope

Windows and exterior doors are excluded from this Verification Method. 

E2/VM2 does not assess the water penetration resistance of the window and exterior door units used with the wall cladding
system. BRANZ EM7 assesses the junctions of window and exterior door units with other elements of the cladding system, but not the units themselves. Instead it relies on the units having been manufactured to resist water penetration when subject to the relevant design parameters for the building.

Although there is currently no Verification Method or Acceptable Solution for the window and exterior door units for mid-rise buildings, window suppliers may be able to demonstrate, through testing, water penetration resistance of the windows when subject to:

• Peak positive and peak negative wind pressures acting on the window or exterior door unit (typically calculated in accordance with AS/NZS 1170.2 including all local pressure factors and internal pressures relevant to the location of the window on the building); and
• The maximum in-plane horizontal movement to which the window or exterior door could be subject.
  • a) are in accordance with the scope of Paragraph 1.0 of E2/AS1, and within the wind zones covered by Section 5 of NZS 3604, and
  • b) have claddings that include a drained and vented cavity of nominal 20 mm minimum depth with minimum ventilation opening of 1000 mm²/m at the foot, including any claddings that require a rigid wall underlay in accordance with Paragraph 9.1.7.2 of E2/AS1, and
  • c) include window and door units that are manufactured to comply with the relevant requirements of NZS 4211, and
  • d) may include buildings based on (a), (b) and (c) above, but with specific engineering design frame elements of at least equivalent stiffness to the framing provisions defined in NZS 3604.

It may also be used for individual buildings that comply with  (a) to (d) above, and that are designed for a specific wind pressure up to a maximum ultimate limit state (ULS) of 2500 Pa.