Vented cold roof systems for buildings with humidity classes between 1 and 4 using VMZINC on an open gap softwood boarding (compatible) substrate.

Standing Seam Roof on open gap boarding (cold, vented):

Vented cold roof system for buildings with humidity classes between 1 and 4 using VMZINC on an open gap softwood boarding (compatible) substrate.
A minimum 50 mm continuous air gap must be left clear beneath the roof boarding. Continuous ventilation openings are made at the ridge and eaves. In order to maintain the integrity of the roof, a VMZINC breather membrane should be installed on the cold side of the insulation, and a vapour control layer appropriate to the building’s humidity levels laid on the warm side of the insulation.
VMZINC must be installed directly over the open-gap softwood boarding without the use of any membrane. The boarding should be clean and dry, 100–150 mm wide, 18 or 24 mm thick, according to the rafter centres.
The roof boards are fixed perpendicularly to the direction of the pitch leaving a 3–5 mm gap between them. They are securely fixed to the structure.

Features and benefits:

A very versatile and easy to install substrate.
Flexible because it also permits complex shapes to be clad in zinc.
Excellent pull-out resistance.
Easy installation using traditional clips.
BRE EN 15804 EPD.

System build-up:

Interior finish;
Vapour control layer;
Insulation;
VMZINC Membrane;
50 mm ventilated air space (minimum);
Rafter;
Batten;
Open-gap timber boarding;
VMZINC Standing Seam.

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Standing Seam Roof on plywood (cold, vented):

Vented cold roof system for buildings with humidity classes between 1 and 4 using VMZINC Plus on a plywood (non-compatible) substrate.
VMZINC PLUS is installed on the plywood. A minimum 50 mm continuous air gap must be left clear beneath the plywood. Continuous ventilation openings are made at the ridge and eaves at least 10 mm wide protected by insect mesh and correspond to BS 5250: 2002.
VMZINC Membrane can be used between the VMZINC PLUS and the plywood, although this is optional but may have the advantage of protecting the plywood prior to the installation of the zinc. The ideal thickness of the plywood is 18 mm and it must be weather and boil proof. WBP plywood is more precisely described as EN 314-2 (bond class 2) and EN 636-2 (timber performance).
It is also recommended to install a vapour control layer on the warm side of the insulation.

Features and benefits:

Provides a continuous rigid deck for the VMZINC PLUS.
Plywood decking is readily available and widely used.
Excellent pull-out resistance.
BRE EN 15804 EPD.

System build-up:

Interior finish;
Vapour control layer;
Insulation;
VMZINC Membrane;
50 mm ventilated air space (minimum);
Rafter;
Batten;
Plywood;
VMZINC PLUS Standing Seam.

VMZINC PLUS:

A product which allows zinc to be installed on ventilated plywood as well as specific warm (non-ventilated) substrates. The product consists of VMZINC (in all finishes) having a 60 µm coating applied to the underside thus allowing a more varied amount of substrates to be used and eliminating the risk of the formation of white rust on the underside of the zinc standing seam panels. VMZINC PLUS resists to an abrasion of 140 L when tested in accordance with ASTM D 968.

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Life Cycle Analysis (LCA):

VMZINC undertakes Life Cycle Analysis (LCA) tests on its products and publishes Environmental Product Declarations (EPDs), such as BRE Environmental Profiles. These provide users with comprehensive, reliable and transparent information on relevant environmental characteristics. The information is also used by VMZINC as the basis for its eco-design approach.

BROOF t4 Standing Seam on Plywood Vented