> as lemmas

1794 W. Felton Treat. Carriages I. i. 34 The compass rails..screwed on the top of the side roof rails; on these the roof boards are nailed.

1848 O. S. Fowler Home for All (1851) 90 Since the roof boards cross these rafters, so as to form an arch the other way, surely no greater solidity or strength can be required.

1940 Chambers's Techn. Dict. 730/1 Roof boards, boards laid on a roof to provide a foundation and an undercovering to the covering materials proper, such as slates, tiles, etc.

2001 Buses Feb. 30/1 From these, he produces assembly drawings, asking questions along the way about variations like the roof boards and destination panels on some of the C5 family.