shown but on the other side only one rafter is shown the latter situation is a typical example of where uneven loading may occur on a roof beam hence in that situation it is desirable that the roof beams have some resistance to torsional forces a suitable roof beam 212 for use in the above described georgian style situation is shown in fig9 of the drawings the roof beam 212 is similar to that of fig7 of the drawing except in respect of the upper capping 220 which has longer sides to meet the glazing panels 214 which are more steeply angles its lower capping 222 which has its facets 224 including a smaller angle than those of the capping 112 39 and flanges 226 of the glazing bar are correspondingly angled relative to the upstanding limb 228 of the glazing bar which is an inverted triangular box section fig1 and 11 show a glazing bar 300 similar to that of fig9 with modifications that will only be described where cross bar 302 and upstanding ducted limb 304 intersect is formed a screw bolt port 306 which enables the glazing bar to be fixed to another component of a roof system by means of a screw bolt or other suitable fixing means through the component and into the port 306 the.