mdm Ventia Platinum Plus Heavy Duty Roof Underlay Instruction Manual

: June 15, 2024
: mdm

Table of Contents

mdm Ventia Platinum Plus Heavy Duty Roof Underlay
Product Information
Product Usage Instructions
ROOF UNDERLAY INSTALLATION PROCEDURE
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

mdm Ventia Platinum Plus Heavy Duty Roof Underlay

Product Information

The Ventia Platinum Plus Heavy Duty Roof Underlay is a high-quality roofing underlay designed for use in New Zealand and Australia. It is suitable for all Wind Zones of NZS 3604 up to and including Extra High. The underlay provides excellent protection against water ingress and is compatible with various roofing cladding materials.

Key Features:

Heavy-duty construction for enhanced durability
Suitable for use with counter-battens
Vertical and horizontal overlaps of at least 150mm
Can be used on roofs with full plywood substrate
Must be covered by roofing cladding within seven days
Can be repaired using ViBest Super Pro flashing tape

Product Usage Instructions

Before installing the Ventia Platinum Plus Heavy Duty Roof Underlay, please ensure that you follow these guidelines:

Installation Procedure

All design and building work must comply with the Ventia Platinum Plus Roof Underlay and BRANZ Appraisal No. 1167 (2021).
The installation should be carried out by a competent and experienced roofer familiar with Ventia Platinum Plus Underlay.
If the installation involves Restricted Building Work, it must be completed by, or under the supervision of, a Licensed Building Practitioner with the relevant Licence Class.
If using counter-battens, we recommend taping all fixings with ViBest Super Pro flashing tape or an equivalent BRANZ appraised tape along the entire length of the truss to seal the penetrations of the counter-batten fixing.

Roof Pitch and Span

Roof Pitch	Span	Roof Underlay Support Required?
Horizontally Installed	Vertically Installed
Greater than 1,200mm	Yes	Yes
1,200mm or less	No	No
Greater than 1,200mm	Yes	Yes
1,200mm or less	No	Yes

Overlap Guidelines

Vertical overlaps must be no less than 150mm.
If installed horizontally, no support is required for spans of 1,200mm or less.
Horizontal overlaps must be no less than 150mm, ensuring that water is shed to the outer face of the underlay.

Repairing Damaged Areas

When fixing the product in windy conditions, exercise caution due to the large sail area created. Any damaged areas of Ventia Platinum Plus Underlay must be repaired before installation:

For larger damaged areas, cover with new material overlapping the damage area by at least 150mm and tape with ViBest Super Pro 150mm wide.
For small tears and holes, tape with ViBest Super Pro flashing tape 150mm wide.

For further technical information and assistance, refer to the provided Technical Literature or contact the manufacturer:

New Zealand: (09) 916 6750, orders@ebuilt.co.nz
Australia: (03) 9116 6351, orders@ozebuilt.com.au
International: +64 9 916 6750, info@ebuilt.co.nz
Website: www.ebuilt.co.nz

Ventia Platinum Plus Heavy Duty Roof Underlay

ROOF UNDERLAY INSTALLATION PROCEDURE

All design and building work must be carried out in accordance with the Ventia Platinum Plus Roof Underlay and BRANZ Appraisal No. 1167 (2021) by a competent and experienced roofer, familiar (knowledgeable) with
Ventia Platinum Plus Underlay. Where the work involves Restricted Building Work, this must be completed by, or under the supervision of, a Licensed Building Practitioner with the relevant Licence Class.
Ventia Platinum Plus Underlay must be fixed, with the printed side facing the exterior, at maximum 300mm centres to all framing members (trusses) with large-head clouts 20mm long, 8 – 12mm galvanized staples, self-drilling screws or proprietary underlay fixings such as Lumberlok Little Grippers. The underlay must be pulled taut (tight) without creases over the framing before fixing. We recommend that all fixings should be taped with ViBest Super Pro flashing tape or an equivalent BRANZ appraised tape along the entire length of the truss to seal the penetration that the fixing has made through the underlay.
If installing Platinum Plus with counter-battens above the underlay, eg BRANZ High Performance Construction Method.
If using counter-battens we recommend that all fixings should be taped with ViBest Super Pro flashing tape or an equivalent BRANZ appraised tape along the entire length of the truss to seal the penetrations of the counter-batten fixing (screwed through the counter-batten).
Ventia Platinum Plus Underlay may be installed horizontally or vertically at roof pitches 3° and above.

Roof Pitch

|

Span

| Roof Underlay Support Required?
---|---|---
Horizontally Installed| Vertically Installed

10° or more

(Minimum 3°)

| Greater than 1,200mm| Yes| Yes
1,200mm or less| No| Yes

Table 1: Roof Underlay Support Requirements – BRANZ Appraisal No. 1167 (2021).

a) If installed vertically at pitches less than 10° must be supported by a corrosion resistant material e.g., Steel Mesh (span no greater than 1200mm).
b) Vertical overlaps must be no less than 150mm.
c) If installed horizontally does not require support (span no greater than 1200mm).
d) Horizontal overlaps must be no less than 150mm with the direction of the overlap ensuring that water is shed to the outer face of the underlay.

We recommend that Platinum Plus be installed horizontally regardless of the roof pitch and that roofs below 10° should have a 200mm overlap and be taped with ViBest Super Pro flashing tape 75mm wide. This is to safeguard against any potential ingress of water in case of a roof leak.

At pitches 10° and greater, Ventia Platinum Plus Underlay can be installed vertically or horizontally with no required support (span not greater than 1200mm).
a) Vertical or horizontal overlaps must be no less than 150mm.
Ventia Platinum Plus Underlay is suitable for use in all Wind Zones of NZS 3604 up to and including Extra High.
Ventia Platinum Plus Underlay must not be exposed to the weather or UV for a total of more than 7 days before being covered by the roofing cladding. NZS 2295, the Building Code standard for roof building underlays, gives guidance that the roof underlay needs to be covered within seven days.
When fixing the product in windy conditions, care must be taken due to the large sail area created.
Any damaged areas of Ventia Platinum Plus Underlay, such as tears, holes, or gaps around service penetrations, must be repaired. Damaged areas can be repaired by covering with new material (underlay) overlapping the damage area by at least 150mm and taping with ViBest Super Pro 150mm wide. Small tears and holes can be taped with ViBest Super Pro flashing tape 150mm wide.
Ventia Platinum Plus Underlay can be used on roofs with full plywood substrate e.g., bituminous shingle roofing systems.
The Technical Literature must be referred to during the inspection of Platinum Plus Underlay installations.