Roofing underlay is used to protect the roof structure below by: providing a second line of defence against water entry; absorbing condensation that forms on the underside of the roof cladding material; reducing air movement in roof spaces; and providing protection against the entry of dust and dirt. Most roofs need underlay Roofing underlays are required with most roofing types, except membrane roofs. 

Batten Type

Timber species should be in accordance with BS 5534. Seek advice from the timber supplier. Battens for single lap tiles, when fixed on rafters spaced at centres up to 450mm, should be 38 x 25mm in section. For rafter spacing’s up to 600mm centre’s the battens should be 50 x 25mm in section.

Installation

Battens should be secured by nailing into each rafter using galvanised or sherardized smooth round nails. Annular ring shank or helical threaded shank nails may also be used. The minimum nail size is 65 x 3.35mm but the resistance of the fixing to wind uplift resistance should be determined using the information given in BS 5534.

We are roofing Underlay and Batten Specialists.