 This is evidenced by the nature of temple construction in the 6th century BC, where the rows of columns supporting the roof the cella rise higher than the outer walls, unnecessary if roof trusses are employed as an integral part of the wooden roof.The indication is that initially all the rafters were supported directly by the entablature, walls and hypostyle, rather than on a trussed wooden frame, which came into use in Greek architecture only in the 3rd century BC.Ancient Greek buildings of timber, clay and plaster construction were probably roofed with thatch.