Glossary

Arch

Types include: Basket arch or Anse de Panier (French, lit. basket handle): three-centred and depressed, or with a flat centre. Chancel: dividing chancel from nave or crossing in a church. Crossing: spanning piers at a crossing in a church. Depressed or three-centred: with a rounded top, but curving inward more at the sides. Four-centred: with four arcs, the lower two curving inward more than the upper, with a blunt central point; typical of late medieval English architecture. Jack arch: shallow segmental vault springing from beams, used for fireproof floors, bridge decks, etc. Ogee (adjective ogival): a pointed arch with a double reverse curve, especially popular in the 14th century; a nodding ogee curves forward from the wall face at the top. Parabolic: shaped like a chain suspended from two level points, but inverted. Relieving or discharging: incorporated in a wall to relieve superimposed weight. Shouldered: with arcs in each corner and a flat centre or lintel. Skew: spanning responds not diametrically opposed. Stilted: with a vertical section above the impost i.e. the horizontal moulding at the springing. Strainer: inserted in an opening to resist inward pressure. Three-centred: see Depressed, above. Transverse: spanning a main axis (e.g. of a vaulted space). Triumphal arch: influential type of Imperial Roman monument, free-standing, with a square attic or top section and broad sections to either side of the main opening, often with lesser openings or columns. Tudor: with arcs in each corner joining straight lines to the central point. Two-centred: the simplest kind of pointed arch.

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.