ABSTRACT
The strength and lightness of aluminium is particularly valuable for entrance doors of all kinds due to the demanding service conditions and traffic requirements to which doors are subjected. Natural anodized frames, basically copies of existing steel casement windows, for example, were fitted to the New Bodleian Library, Oxford, and in a new office block in Banbury. The phenomenon can manifest itself under appropriate conditions by condensation on the interior surface of the window frame. The use of hollow sections not only provides a combination of lightness, strength and rigidity, but importantly, also enables many features such as multi-locking devices, bolts, spring closers and various security features to be concealed within the frame. Wooden shutters, of course, are commonplace in Europe, where windows are designed to open inwards rather than outwards as in the UK. Rigid and reliable corner construction is achieved by mitring and mechanically cleating.
