34 includes a flat vertical plate 48 the rear surface of which mounts against the flat face of the respective rafter 14 a flat horizontal projection 42 projects forwardly from the vertical plate 48 and serves as an upper stop for the rigid panel 32 two spacer legs 38 40 on the vertical plate 48 project upwardly to a higher elevation than the horizontal projection 42 and terminate at free ends 44 which abut the bottom surface of the roof sheathing 12 as shown in fig2 the free ends 44 lie at a first elevation and the horizontal projection 42 lies at a second elevation lower than the first elevation the vertical distance between the first and second elevations defines the ventilation gap 30 first and second spikes 50 project rearwardly from the vertical plate 48 and are used to mount the brackets 34 onto the rafters 14 in this embodiment both the upper stop 42 and the spikes 50 are stamped out of the plate 48 and are bent in their respective directions with the upper stop 42 projecting forwardly and the spikes 50 projecting rearwardly the spikes 50 have a triangular profile ending in a sharp point 52 so they may be easily driven into the rafter 14 as by hammering to secure the bracket 34 to the rafter 14 as shown in fig2 the spacer legs 38 40 also define small through openings 62 so nails may be driven through the openings 62 to secure the bracket 34 to a rafter 14 in addition to using the spikes 50 if desired the bracket 34.