Technical Guidance

Question:

Does the guidance for joining battens over a truss or rafter apply to all battens regardless of the batten gauge?

Considerations:

• NHBC Standards 7.2.17 states that not more than one in four battens should be joined over one truss or rafter.

• BS 8000:6 ‘Code of practice for slating and tiling of roofs and claddings’ accepts a different jointing arrangement where batten gauges are less than 200mm.

• BS 5534 ‘Code of practice for slating and tiling’ gives a minimum length for tiling battens.

Answer:

Joints in battens should generally be not more than one in every four battens over each truss or rafter (see diagram below).

Where the batten gauge is less than 200mm up to three battens joints may be made together in any 12 consecutive battens on the same truss or rafter (see diagram below).

Except for very narrow sections of roof each batten should span over at least three supports.