Purlins – These are long pieces of timbers that are normally seen half way along the rafters and act like beams to reduce the span (unsupported length) of the rafters
Tulathau – Maent yn ddarnau hir o bren a welir fel rheol hanner ffordd ar hyd y ceibrennau, ac maent yn gweithredu fel trawstiau i leihau rhychwant y ceibrennau (yr hyd na chynhelir).