Working Detail: Cotes Farm by Evans Vettori
[WORKING DETAIL 07.02.08] A copper-covered mansard roof with projecting verge
The house is made up of a restored stone barn with a pitched roof of stone slates, a kitchen link with a patent-glazed pitched roof and a new wing with a copper-covered mansard roof. The three gables- of barn, kitchen link and mansard - rise one above the other.
Three large bedrooms and three bathrooms fit comfortably within the mansard shape. They are lit by gable the main bedroom is lit with a ‘light-scoop’ - a fixed light with a copper-clad hood which tapers to merge with the copper roof.
The copper roof sheet was laid with standing seams; it accommodates the 10º and 75º mansard slopes and its weathered finish complements the natural wall and roof materials next to it.
The new wing has insulated cavity walls with an outer leaf of split-faced millstone grit from Waddington quarry near Clitheroe, Lancashire. The mansard roof structure is a frame of 152 x 152mm and 203 x 203mm UCs which support an insulated structural deck system on which the copper sheets were laid. The copper roof and deck project at the gable, appearing ‘to float over the walls’. This visual separation between planes is emphasised by the verge detailing; a soldier course of cut blue bricks with blue-grey mortar joints runs just below the verge, with a 175 x 140mm stone coping running below it to frame the coursed split-stone wall. The projecting copper verge, together with the brick and coping courses, follows the double slope of the mansard to the eaves.