Hammerbeam roof
A Hammerbeam roof is a decorative, open timber roof truss typical of English Gothic architecture and has been called "...the most spectacular endeavour of the English Medieval carpenter." They are traditionally timber framed, using short beams projecting from the wall on which the rafters land, essentially a tie beam which has the middle cut out. These short beams are called hammer-beams and give this truss its name. A hammerbeam roof can have a single, double or false hammerbeam truss.
Design
A hammerbeam is a form of timber roof truss, allowing a hammerbeam roof to span greater than the length of any individual piece of timber. In place of a normal tie beam spanning the entire width of the roof, short beams – the hammer beams – are supported by curved braces from the wall, and hammer posts or arch-braces are built on top to support the rafters and typically a collar beam. The hammerbeam truss exerts considerable thrust on the walls or posts that support it. Hammerbeam roofs can be highly decorated including ornamented pendants and corbels, with church roofs often including carved angels