Aluminium Rainscreen Cladding Systems, Supplied and Installed

BDF Architectural is a specialist aluminium rainscreen cladding contractor: we supply and install aluminium rainscreen cladding systems, a drained and back-ventilated outer skin of aluminium panels on a framing system in front of the building's wall, on new build and re-cladding projects for main contractors, developers and architects. We install across London and the South East and supply UK-wide. A package can cover the brackets and rails behind the cladding, the aluminium panels themselves and the junctions with windows, curtain walling and other façade systems, so one team is responsible for the elevation.

The panels take most of the rain; what gets past runs down the cavity and drains out at the base, and air moving through the gap dries it out, so the wall and insulation behind stay dry. Aluminium suits the outer skin because it is light, takes almost any colour or finish, and can be formed into cassettes, flat sheets, perforated or profiled panels. Our guide What is rainscreen cladding? explains the build-up, joint types, insulation and fire rules in detail; this page sets out the aluminium rainscreen systems we install and how a package is priced and delivered.

There are three main panel types. Cassettes are sheets folded into shallow trays with returned edges, hung on or fixed to the rails, giving a flat face with crisp, regular joints, and they can be made with hidden fixings. Flat sheets are cut to size and fixed directly to the rails with rivets or screws, which is simpler and usually lower in cost. Perforated and profiled panels add texture, screen openings and plant areas, or shade glazing. Panel size, sheet thickness and the joint pattern are set by the design and checked against the wind load on each elevation.

Fixing is either visible or concealed. Exposed fixings, rivets or screws through the panel face, are colour-matched and quick to install. Concealed fixings, such as cassettes hooked onto pins or clips on the rails, keep the face clean and usually let individual panels be removed later. Either way, the panels are fixed to allow for thermal movement, and the joints are either left open, so the cavity can drain and ventilate, or closed with a baffle behind.

Finishes are powder-coated in any RAL colour, anodised, or mill finish. The finish is specified with the exposure of the site in mind, and the same colour can be carried across the windows, curtain walling and trims so the elevation reads as one.

Fire performance is the first question on any rainscreen. In England, the external walls of relevant buildings, such as blocks of flats, with a storey 18 metres or more above ground must use materials of class A2-s1,d0 or better, and every external wall is specified against Approved Document B and the fire strategy. Uncoated solid aluminium sheet is non-combustible, and powder-coated solid aluminium panels are typically classified A1 or A2-s1,d0 on the test evidence for the coating. Aluminium composite panels are a different product: those with a polyethylene core are not permitted on relevant buildings, and composite panels with a mineral-filled core are classified on their own test evidence. The classification of the panels, insulation, membranes, brackets and cavity barriers is confirmed at technical review before anything is ordered.

The junctions are where rainscreen goes wrong. Window heads, sills and reveals, parapets, soffits and the base of the wall all need closures and trims that keep the cavity drained and ventilated, and cavity barriers are fitted around openings and at compartment floors and walls, as Approved Document B and the fire strategy require, to stop fire spreading through the cavity. We draw these junctions together with the windows and curtain walling, so the interfaces are designed by the same team that installs them.

On re-cladding projects, the existing cladding comes off and the wall behind is surveyed before the new system is designed: what the framing can fix into, the condition of the insulation and cavity barriers, and the window interfaces all affect the design, and pull-out tests on the existing substrate are commonly needed to confirm what the anchors can carry. A new aluminium rainscreen can usually be designed around the existing window openings, with new trims and closures at the reveals.

A rainscreen package normally runs from technical review of the drawings and the fire strategy, through design of the framing and brackets to the wind load on each elevation, fabrication drawings and panel samples for approval, to fabrication in our West Drayton facility, sequenced delivery, installation, inspection and handover records. The framing, insulation and cavity barriers are hidden once the panels are on, so inspection during installation matters as much as the panels themselves. We can price rainscreen on its own or with curtain walling, unitised façades, windows and brise soleil, so the interfaces sit with one contractor.

To price a rainscreen package, send elevations and sections, the panel type, fixing method and finish, the fire strategy and building height, details of the backing wall and structure, and programme dates. For re-cladding, include any survey of the existing wall.