Struts support underpurlins, ridgeboards, hips and valleys from walls or strutting-type beams (never hanging or counter beams), set vertical to perpendicular to the rafters, birdsmouthed or halved, restrained if not vertical, framed and braced where steeper than perpendicular up to 60 degrees; fan struts are paired at up to 45 degrees, at most 4.5 m long and 3.0 m apart at the purlin. Collar ties are fitted in all coupled roofs, immediately above underpurlins or no higher than two-thirds of the roof rise, sized from the table and bolted or nailed as their length requires.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.