In general, an inclined timber in a roof truss supporting a purlin
Alternative(s): Principal
A) Box-frame construction C) Closed truss
a) Sill beam b) Post c) Stud d) Transverse beam e) Common rafter f) Couple g) Principal h*) Collar i) Queen strut j*) Tiebeam k) Axial beam
A) Base cruck B) Spere truss C) Secondary truss D) Raised cruck E) Upper cruck
a) Wall plate b) Cusp c) Cusped windbrace d) Ridge piece (ridge purlin) e) Principal rafter f*) Plate g) Purlin h) Cranked tiebeam l) Ceiling beam