Technical tips for installing roofing batten

When you think of a secure pitched roof, battens aren’t always the first thing that comes to mind because they are hidden by the roof covering. However, they are actually crucial to the overall security of the roof, providing a reliable anchor that tiles or slates can be securely fixed to. Battens also play a part in ensuring the rigidity, durability and weather tightness of the finished roof.That’s why, whether you’re working on a new build or a refurbishment project, all battens need to be installed in accordance with BS 5534: 2014. Here are our top tips on storing, setting out and fixing battens to make sure your roof is compliant with the Standard.

Preparation and storage

1 – Only ever use a roofing batten that is marked BS 5534 compliant – make sure you check the stamp on the batten yourself.

2 – Store battens and counter battens on sufficient bearers to prevent sagging or twisting. Protect them from water saturation when stored in bales or bundles horizontally.

Batten length, size and spacing

3 – Before installing the battens, check you have the size and spacing right as this can have a direct influence on the weather tightness of the roof, as well as the finished appearance.

4 – The appropriate batten size will depend on the span of the rafters and type of roof covering you are using. BS 5534 includes a table of recommended minimum batten sizes. For example 25 x 50mm battens should be used for single-lap interlocking tiles when laid on rafters with a 600mm span.

5 – Battens should be fixed to rafters set at centres not more than 600mm apart. They should span at least three rafters and be at least 1.2m long.

6 – No more than one in four battens should be joined over one truss for gauges over 200mm. For gauges less than 200mm, there can be a maximum of three consecutive joints in any twelve battens. Using a spread of batten lengths is a good way to achieve the above two requirements, as it results in staggered joints.

Fixing

7 – When you’re ready to secure the battens to the rafters, ensure you’re using the right nails. BS 5534 states that the nails used to fix battens to rafters should usually have a diameter of at least 3.35mm. The nails should provide a minimum of 40mm penetration into the rafter, so a nail length of 65mm is generally recommended.

8 – Start at the lower edge of the roof, nailing the batten into place at the centre of the rafter. Joints should be directly over rafters, with the batten square cut, tightly butted and skewed nails.

9 – If a batten end is to be set in mortar, make sure an appropriate preservative treatment has been applied. This is not required when using a dry fix system.

Wall fixing

10- When fixing to a wall, fix specified battens to boarding /sheathing sarking in line with vertical supports, or to masonry wall as specified. Secure counter battens to masonry walls with improved nails or with plugs and screws.

Other battens considerations

11 – When fixing dry verges to battens, under the new BS 8612 Standard, they can no longer be installed just with a nail fixing into the end grain of the batten. Instead, mechanical engagement must be achieved when fixing a dry verge to the batten. Using a system with a batten end clip can make this easier.

12 – Counter battens - If you’re using a vapour permeable (breathable) membrane with a close fitting roof covering, such as shingles, then it needs to be counter battened to allow ventilation of the batten space. The position of the first batten should be the batten gauge plus half the thickness of the batten. The batten gauge thereafter is based on the pitch of the roof.