St. Mel’s Cathedral Longford, a protected structure, built in the neo-classical style between 1840-1893, was severely damaged by a fire on the 25th of December 2009 in which the interior of the building together with the roof and timber floors were completely destroyed. Design ID were first contacted in February 2013 by GEM Joinery after trawling the land for structural engineers with experience in designing traditional timber structures. It was a fortuitous contact, as Design ID has the previous day witnessed the installation of virtually identical Queen post trusses they designed at Larne Market Yard, County Antrim. Longford Cathedral offered a great opportunity for Design ID to build upon their experience and to assist GEM with this important element of the restoration works. The primary roof structure consists of 13 Queen Post trusses along the length of the cathedral support purlins, which in turn support the common rafters and roof build up. King post trusses span the Transepts and finally lean-to trusses span the side aisles. During the design of each timber joint, consideration was always first given to the use of traditional Mortise and Tenon joints. Only once the capacity of such a joint was exceeded, would steel strapping or other means of jointing be introduced. The second element of design was focused on the structure behind the spherical Apse Ceiling – the structure in itself is a work of art that like the roof trusses, will never be seen by the general public. In the absence of any accurate historical information on the form of the Apse Ceiling support structure, Design ID and GEM set about recreating a (virtually) all timber structure to sit within the complex and challenging constraints of the non-symmetrical support walls and the already installed new roof trusses.
Client: GEM Manufacturing Co Ltd