DriStud FRU 38 are white synthetic tri-laminate roofing underlays that are water resistant, vapour permeable and fire retardant. The FRU 38 is a self-supporting, roof underlay.
DriStud FRU 38 is designed as self-supporting roofing underlay. Once installed, it provides a
secondary protective weather resistant layer over roof framing (truss or rafter). DriStud FRU
38 is air-impermeable layers behind the roof cladding.
- CodeMark™ Certified
- Self Supporting
- Can be installed over timber and steel roof framing
- Fire Retardant
- Durability: 50 years
- Direct fix with absorbent and non-absorbent cladding
- Direct fix metal cladding
Scope of use
DriStud FRU 38 is a synthetic roofing underlay that are intended for use on new and existing buildings in wind zones up to and including "Extra High", as desfined in NZS 3604:2011.
New Zealand Building Code (NZBC)
The product will, if employed in accordance with the supplier's installation and maintenance requirements, assist with meeting the following provisions of the building code:
- Clause B1 Structure: Performance B1.3.1, B1.3.2, B1.3.3(a), B1.3.3(h)
- Clause B2 Durability: Performance B2.3.1(a), B2.3.2(b)
- Clause C3 Fire affecting areas beyond the fire source: Performance C3.4(c)
- Clause E2 External moisture: Performance E2.3.1, E2.3.7(a), E2.3.7(b), E2.3.7(c)
- Clause F2 Hazardous building materials: Performance F2.3.1
The product has and can make available the following additional evidence to support the above statements:
DriStud FRU 38 is intended for use on buildings designed in accordance with NZS 3604:2011 paragraph 1.1 and
in wind zones up to and including ‘Extra High’.
DriStud FRU 38 is designed to be used as a replacement for standard kraft paper roof underlay.
It can be
installed over both timber and steel framing to ensure a dry roof cavity. DriStud FRU 38 can be used under:
Profiled metal roof claddings
However, DriStud FRU 38 must not span more than 1200mm between adjacent supports.
Overlaps / support
DriStud roofing underlays must be installed with all writing and imagery facing out and with
as minimal a number of overlaps as possible. Where overlaps are unavoidable a lap of 150
mm minimum must be used. DriStud FRU 38 must not span more than 1.2 m between
adjacent supports. The installation of DriStud roofing underlays must be in accordance with
paragraph 8.1.5, E2/AS1.
If the roofs pitch is 10° or less, DriStud roofing underlays must be run horizontally with the
higher layers sitting on top of the lower layers. If installing on a roof with a pitch greater
than 10° then DriStud roofing underlays may be installed either horizontally or vertically.
When DriStud roofing underlays are being used in conjunction with masonry tiles, antiponding
boards should be used at the lower edges of the tiles.
DriStud roofing underlays do not require any maintenance but when exposed through
removal of roof cladding, the underlays must be inspected and any damaged areas repaired
TCL Hunt Ltd warrants that all DriStud roofing underlays will be free from manufacturing
defects. Upon receiving of DriStud roofing underlays, it is recommended that a visual check
is made. Where defects are observed, these will be replaced at the discretion of TCL Hunt,
provided that they are returned to point of purchase.
If installed in accordance with TCL Hunt installation requirements, TCL Hunt warrants that
DriStud roofing underlays will comply with all relevant provisions of the NZ Building Code.
TCL Hunt is confident that all DriStud roofing underlays will have a serviceability life of 50
years provided that:
- the balance of the external wall is installed in accordance with the NZ Building Code,
- all necessary maintenance is undertaken in respect of the external wall system.
Please refer to DriStud website www.dristud.co.nz for more information on warranty and
||ISO 9001 (Quality Management)