GB749580A - Improvements relating to roof structures - Google Patents

Abstract

749,580. Roof trusses. KERMODE, S. Aug. 14, 1953 [Aug. 13, 1952], No. 20388/52. Class 20(4). A roof truss particularly for use in single storey buildings which are preformed in sections and assembled on site to form a permanent building comprises a web 11 formed from panels of plywood, hardboard, &c., which extend the full depth of the truss and constitute the principal load carrying member. The web 11, formed by glueing several panels face to face, is stiffened by timber battens 13, 14 nailed to each side of the web along its top and bottom edges, and by timber battens 15 extending across both sides of the web. Capping boards 16 are secured along the top edge of the truss boards 17, being secured to the bottom edge which is curved to accommodate an arched ceiling. The web 11 has openings 18, Fig. 4, to receive purlins 20 which are fixed by screws to the framing of the truss, the flanges of the boards 17 being used to support the ends of bearer beams 21, Fig. 3, which have boards 26 secured e.g. by glue, to their under surfaces for supporting ceiling boards 22 clamped in position by wedges 30 inserted through holes 31 in the beams 21. A parallel series of beams 21 is arranged between each pair of adjacent roof trusses and between each gable and the nearest truss. Each gable is made up of half gable sections 32, Fig. 5, each of which comprises timber framing 33 faced on the outer side with panels, e.g. of plywood, and having blocks 35 to support the purlins 20. A curved facing 37, e.g. of hardboard, is inserted below the framing 33, a curved bar 38 being arranged along the top of the facing 37 for supporting the ends of adjacent ceiling bearer beams. Specification 749,549 is referred to.