Rainscreen Cladding

Specification
Uninsulated Cassette panels
The cassette panel system was designed by HW Architectural Limited primarily as a rainscreen decorative feature applied to insulated structure.
The system is a series of interlocking flat face aluminium tray panels with concealed fixings and perimeter joints forming a 25mm shadow line feature. The panels in the decorative rainscreen form are not insulated and are situated in front of a waterproof membrane and insulated structure.
The membrane is a three layer polyethylene film with a density of 140 g/m2.
Panels can be rectangular or square and are formed with return ends, top fixing flanges and bottom locating hook flanges. Panel thickness is dependent on scheme size and scope and consideration is given to individual enquiries to determine thickness in line with panel flatness requirements.
Maximum module sizes are 3.6 metres wide x l.36 metres high although consideration may be given to schemes outside this module maximum.

Classification
A system of interlocking flat face metal tray panels with concealed fixings, perimeter joints form a 25mm shadow line feature.
The panels are not insulated and form the rain screen in front of a waterproof membrane and insulated wall.
The system can be integrated with adjacent glazing systems and can be fixed vertically or sloping.

Materials
The metal trays are formed out of aluminium alloy sheet in accordance with British Standards as follows:
A) BS: 1470 alloy designations 1200 H4 3 l03/H4, or 5251 /H3 for use on paint finished trays.
B) BS:4300/7 alloy designation A5005 H4 for anodised trays.
The waterproof membrane is a three layer polythene film with a density of I 40 g/m2, a tensile strength of 685 N/50mm and a tear strength of 306N.
All fixing screws shall be stainless steel manufactured in accordance with BS 3111 pt 2 and BS 6105.

Construction
The panels are rectangular or square and are formed with return ends, top fixing flanges and bottom locating hook flanges.
The dimensions of these formed features is an integral aspect of the design and cannot be varied.
The panels can be fixed to vertical battens, exterior grade plywood or to aluminium supporting members.
It is usual for the battens or plywood to be supplied and fixed by the General Contractor.
Fixings are by means of screws securing a specially designed cleat fitted along the top edge of panels.
The bottom edge is hook located into this same cleat.
The waterproof membrane is supplied in rolls and is lap jointed horizontally with 150mm laps. It is secured to the battens with stainless steel or aluminium staples.

Finishes
Anodised aluminium. Anodising is by Qualanod approved finisher to British Standards l615 and 3987 by the Anolok process. Natural and black anodising together with a range of five bronzes are available. It is recommended that samples of top and bottom colour limits are obtained to indicate the variation in shade for any given colour. It is not possible to maintain exact colour matches in any batch of panels. Polyester Power Paint. The recommended finish is Syntha Pulvin which is applied by an approved applicator. This finish complies with the requirements of BS 3900 and BS 6496.

Insulated Rainscreen Systems
Alternatively the cladding system may be incorporated into the modular curtain wall systems supplied by HW Architectural Limited complimentary to the vision and ventilation aspects of the curtain wall.
Principles of rainscreen cladding are maintained with the incorporation of insulation and internal lining panels to produce a complete and comprehensive wall cladding system.
Incorporation into a curtain wall system reduces the needs of the structural support element to a more traditional support system of columns and purlins, with structural curtain walling members applied vertically and horizontally.
Design services and specification preparation by HW Architectural Limited are available upon request for this system.