It is used for spans between 4 and 5.5 meters. A collar of the same width as the rafters is placed on each pair of rafters and is attached at a height of one-half to one-third of the vertical height between the wall and the ridge. The collar is dovetailed to the rafters and bolts can be used for additional security. The collar must be kept as low as possible to provide maximum strength to the roof.
Leave a Reply