• Over 35 Years of Trading
  • £3m+ Stock Value
  • Best Price Promise
  • 9 Branches in London

Batten – Not just a fixing point for your tiles

Once the roofing felt or underlay has been fitted to the rafters, the next stage of a roofing project is to fix the battens ready for installation of the tiles or slates.

iko breathable membrane installed over the rafters and under the batten

The battens should be fitted as soon as possible after the underlay, to prevent wind and weather damage.

What are Battens?

Battens are the lengths of wood that are laid in-between the rafters to secure the roofing felt and to accept the tiles or slates when they are fitted. Battens are an important element of the roofing structure and serve a number of purposes, as defined by the British Standard 5534:

  • They give rigidity to the roofing structure, particularly when modern trussed rafters are used.
  • They are used to locate the roof covering in straight, consistent rows, and provide a strong anchor for the nails or clips used to secure the tiles or slates. A sub-standard batten may not provide sufficient pull-out resistance for the fixing nails, which could result in failure of the roof later on.
  • The battens are load-bearing, and must be strong enough to carry the dead loads, the weight of the roof covering and potentially standing snow and the imposed loads caused by wind.

Batten Standards

The rules governing the size and type of battens to be used for roofing are covered by the British Standard Code of Practice for Slating and Tiling, BS 5534: 2003+A1:2010. The standards dictate the type and size of the battens to be used for various rafter spacings and roof coverings, and any defects which are, and are not acceptable. Typical defects to timber that must be considered before selecting battens include:

  • Wane
  • Slope of grain
  • Face knots and side knots
  • Resin pockets
  • Insect attack
  • Rot and decay
  • Splits and fissures
  • Preservative treatment

Each piece of batten should be clearly marked with the following:

  • The name and identity of the supplier
  • The sectional size
  • The timber species type
  • The grade of the batten, e.g. Graded BS 5534

The size of the batten is also very important to ensure that the roof is strong enough, and the basic minimum sizes of batten are laid out in BS 5534, depending on the span of the rafters and the type of slate or tile to be used. Any batten measuring less than 25mm in thickness can be considered €˜under-measure' and should not be used as it could become unstable.

  • For natural double lap slates (sized or random), the minimum width is 50mm and depth 25mm, for a span of up to 600mm.
  • For natural double lap slates (fibre cement or concrete), the minimum width is 38mm and depth 25mm, for a span of up to 450mm; and 50mm width, 25mm depth for a span of up to 600mm.
  • For double lap clay and concrete tiles, the minimum width is 38mm, and depth 25mm for a span of up to 600mm.
  • For single lap clay and concrete tiles, the minimum is 38mm width and 25mm depth, for a span of up to 450mm; and 50mm width and 25mm depth for a span of up to 600mm.

Installation

The manufacturer of the slates or tiles should also provide the recommended spacing up the roof for the battens. This is also known as the gauge and will vary according to the pitch of the roof and the degree of exposure. It is useful to cut a piece of timber to the correct length of the gauge to use as a spacer when positioning the battens later on.

  • Starting at the lower edge of the roof, position the first batten so that the slates or tiles will provide the necessary overhang over the fascia when fitted.
  • Measure the distance at both ends of the roof then run a piece of string across the roof, making sure the distance is consistent across the length of the roof.
  • Cut the first batten to size then nail it securely to each rafter. The minimum nail size is 65mm x 3.35mm, but there is also guidance in BS 5534 to determine the resistance of the fixings required to prevent wind uplift.
  • When the lower batten is fixed, use the gauge spacer you cut earlier to determine the position of the next batten, and nail it in place.
  • Repeat this sequence for each batten up to the top of the roof.
  • At verges, the battens should be positioned within approximately 25mm of the edge of the underlay.
  • At hips, you should leave enough space between the battens from the two sides to allow a batten to be fixed along the top of the hip board.

If any of the horizontal underlay overlaps do not correspond with a batten, you can fix an intermediate batten for the purpose of holding down the underlay. If you are using tiles, be careful to leave enough room for the next to the primary batten for the tile nib.

Any minor cutting errors that might have been made will add up over the course of the entire roof, and this may mean that you need to deviate from your gauge when fixing the top batten. If this is the case, you should adjust the gauge as necessary when securing the top batten.

Health and Safety

Roofers account for approximately 24% of all workers who are killed by falls from height at work. It is essential when fitting a roof that you take extra care to ensure it is done in a safe manner. Some safety tips to consider are:

  • Wind speed must be considered when working on the roof. If the wind speed is in excess of 17mph, any work with roofing felt or underlay should be stopped until conditions improve. Laying of slates, tiles and battens at roof level should also cease if wind speeds exceed 23mph.
  • Open rafters can also present a safety issue when working on the roof, and the Work at Height Hierarchy' in the Health and Safety Executive's guidelines details reasonably practicable' measures which you can put in place to minimize risk.
  • Roof ladders are also covered by the guidelines, which detail a number of criteria that must be met to ensure that safe practice is adhered to when climbing and working on ladders. The full guidelines are available here

When the battens have been fixed to the roof, the next step is to lay the tiles or slates. You can purchase your roofing batten online here.

Published at: 18-12-2014

Our Top Videos.

How to install a Velux Integra Electric Roof Window (5 Parts)

In this five-part guide, we take you through the full installation of a Velux GGU Centre Pivot Integra Roof Window onto an...

Read More

How to install a Duratech Centre-Pivot Pine Roof Window

Once you begin unpackaging the window, you’ll find in the box the brackets, the handle and the fixings. And there will also be some instructions...

Read More

How to install a Velux Centre-Pivot Roof Window (4 Parts)

In this four part guide, Mark Dymond – Velux Technician installs a Velux GGU Centre Pivot Roof Window onto an Interlocking Tile Roof...

Read More

Ideas & Advice

How-tos, tutorials and videos

How and why to use or snap a chalk line

Chalk lines are the fastest way to mark straight guidelines on flat surfaces. They are used extensively in the building and construction industry to speedily and accurately ‘draw’ straight lines between two points. Chalk lines are inexpensive tools...

Skylight Blinds: A Guide To The Different Types

Like many household product, blinds for skylight windows come in all shapes, sizes, and materials. Some are designed with a tangible purpose in mind, while others are more for show. One thing’s for sure - buying any type of skylight blind...