Description

DriStud EcoDri FR, DriStud RU22, Dristud RU24, Dristud FRU36 and DriStud FRU38, are self-supporting roof underlays which may also be used as wall underlays.

DriStud EcoDri FR, DriStud FRU36 and DriStud FRU38 are fire retardant. DriStud RU22 and DriStud RU24 are non-fire retardant.

1. DriStud EcoDri FR is a fire-retardant synthetic tri-laminate water resistant, absorbent and vapour permeable underlay manufactured from recycled polypropylene. DriStud EcoDri FR is available in a range of top-face colours, primarily in darker shades. The colour may vary depending on the recycled materials used.
2. DriStud RU22 and DriStud RU24 are non-fire retardant, synthetic tri-laminate water resistant, absorbent and vapour permeable underlays.
3. DriStud RU22 is grey-faced and DriStud RU24 is black-faced.
4. DriStud FRU36 and DriStud FRU38 are fire-retardant synthetic tri-laminate water resistant, absorbent and vapour permeable underlays. 
5. DriStud FRU36 is white faced and DriStud FRU38 is white.

All products are branded with DriStud branding and the specific product name.

Scope

1. DriStud EcoDri, DriStud RU22, DriStud RU24, DriStud FRU36 and DriStud FRU38 Roof Underlays are certified for use as a roof underlay:

• a. on buildings situated in wind zones up to and including Extra High (as set out in NZS3604) with a minimum roof pitch of 3°,
• b. under masonry tiles, terracotta tiles, metal tiles, profiled metal claddings (subject to Condition 5(d) below), slate and composite panels,
• c. installed horizontally or vertically (subject to Conditions 5(b)(ii) and 5(c) below),
• d. installed on timber or steel roof framing.

2. DriStud EcoDri, DriStud RU22, DriStud RU24, DriStud FRU36 and DriStud FRU38 Roof Underlays are certified for use as a wall underlay with absorbent or non-absorbent wall claddings directly fixed to the frame or installed over an 18 mm minimum drained cavity or with masonry veneer, in accordance with NZBC Acceptable Solution E2/AS1 for timber framed buildings or NZBC Acceptable Solution E2/AS4 for steel framed buildings.

3. DriStud EcoDri, DriStud RU22, DriStud RU24, DriStud FRU36, and DriStud FRU38 Roof Underlays are not certified for use in buildings where the underlay is exposed to direct or reflected UV light.

4. DriStud EcoDri FR, DriStud FRU36, and DriStud FRU38 Roof Underlays are certified for use as a roof or wall underlay in locations exposed to view in an occupied space.

5. DriStud EcoDri FR, DriStud FRU36, and DriStud FRU38 Roof Underlays are certified for use as an air barrier.

6. DriStud EcoDri FR, DriStud RU22, DriStud RU24, DriStud FRU36 and DriStud FRU38 Roof Underlays:

• a. shall be installed in accordance with the applicable Installation Guide (available at www.drispace.co.nz):
  • DriStud EcoDri FR Installation Guide Rev 1.0, September 2024,
  • DriStud RU24 Installation Guide Rev 5.0, September 2024,
  • DriStud RU22 Installation Guide Rev 4.0, August 2023,
  • DriStud FRU36 Installation Guide Rev 5.0, September 2024,
  • DriStud FRU38 Installation Guide Rev 4.0, September 2024, and
• b. when used as a roof underlay:
  • i. shall be supported by corrosion resistant mesh or alternative e.g. plastic strapping where:
    • 1) the span exceeds 1200mm or
    • 2) the underlay is installed vertically where the roof pitch is less than or equal to 10°, or
  • ii. may be installed horizontally (with upper layers overlapping the lower layers) without support, for roof pitches 3° or greater, provided the underlay is installed flat and taut, and
  • iii. shall not be installed directly under direct-fixed trapezoidal or trough profile metal roof cladding, and
• c. shall be separated from fireplaces, heating appliances, flues and chimneys in accordance with the requirements of NZBC Acceptable Solutions C/AS1 and C/AS2, Paragraph 7.5.9 for the protection of combustible materials, and
• d. shall be protected from direct sunlight following installation within the following times:
  • i. 7 days for DriStud RU22 and DriStud FRU36
  • ii. 21 days for DriStud EcoDri FR, DriStud FRU38 and DriStud FRU24.