Glossary

Base

Moulded foot of a column or pilaster. An Attic base is the form used on an Ionic column, with two large convex rings joined by a spreading convex moulding.

Crucks

(lit. crooked): Pairs of inclined timbers (blades), usually curved, set at bay-length intervals in a building; they support the roof timbers and, in timber buildings, also support the walls. Base crucks have blades rising from ground level to a tie-beam or collar-beam which supports the roof timbers. Full crucks have blades rising from ground level to the apex of the roof, serving as the main members of a roof truss. Jointed crucks have blades formed from more than one timber; the lower member may act as a wall-post; it is usually elbowed at wall-plate level and jointed just above. Middle crucks have blades rising from halfway up the walls to a tie or collar-beam. Raised crucks have blades rising from halfway up the walls to the apex. Upper crucks have blades supported on a tie-beam and rising to the apex.

Rafters

Inclined lateral timbers supporting the roof covering. Common rafters: regularly spaced uniform rafters placed along the length of a roof or between principals; also called coupled rafters. Principal rafters: rafters which also act as principals, i.e. the paired inclined lateral timbers of a truss.