Curtain Walling

Curtain walling is a glazed building enclosure, which is designed to carry its own loads (self weight and dead loads) and imposed loads from the environment. Fixed panes, opening lights and doors can be incorporated into the basic framework. Mullions normally run full height and the transoms are fixed between. Mullions can be supported from the bottom (‘propped’) or from the top (‘hung’).

CWD curtain wall systems can be either mullion or transom drained and are suitable for vertical or sloping applications. The inside members are separated from the external capping resulting in an efficient thermal barrier. All systems are designed to satisfy the wind loading requirements of BS6399 Part 1.


Aluminium profiles are extruded from aluminium alloy 6063 complying with the recommendations of BS EN 755-9.


Curtain wall sections can be finished in either organic powder coat to BS6496 or anodising to BS3987. Certain systems are available with different colours externally and internally.


Mullions generally are square cut and fixed to the building using brackets secured back to the steel or concrete structure. Transom rails are then installed as required between the mullions and fixed with cleats and/or stainless steel screws. The glazing is retained in the rebates by face fixed pressure plates, which are then finished with clip-on caps externally.


The glazing (glass, panels, opening lights or doors) is set in EPDM gaskets, which are retained in undercut grooves in the aluminium profiles and held secure by pressure plates. Glass conforms to BS6262 and BS6206 for both thickness and type. Double glazed units conform to BS EN1279.


CWD curtain walls have been tested to BS6375 part1, to the CWCT requirements and to European standards. It has achieved at least the following results:

600 Pascals Air Permeability
600 Pascals Water-tightness
2000 Pascals Wind Resistance

This should be sufficient for any location within the UK.

The thermal performance of our curtain wall satisfies or exceeds the current requirements of approved document L when glazed with glass of the appropriate ‘U’ value.
The security provided by a curtain wall is largely dependent on the windows and door modules incorporated within it.


CWD pursue a policy of continuous development and reserve the right to change their product specifications without prior notice.