For timber battens used to support tiles or slates, use battens that are correctly graded and marked to BS 5534 where the roof specification requires them. Do not assume an ordinary treated timber batten is equivalent because it has the same dimensions.
25 × 38mm and 25 × 50mm can both be graded roofing-batten sizes
Both sections are used in pitched-roof specifications. The roof covering and support span determine the minimum section, which is why the size alone cannot tell you whether a piece of timber is suitable.
Wern-Wood's BS 5534 Roofing Batten is 25 × 50mm × 4.8m. Our green 25 × 38mm and 25 × 50mm treated battens are not sold as graded tile or slate battens.
Check the individual markings rather than relying on colour
Correctly graded roofing battens are individually marked so their source, size and grading can be identified. Coloured treatment can make products easy to recognise in the yard, but colour by itself is not proof of BS 5534 compliance.
Graded roof battens also have a site-safety role
NFRC guidance explains that only correctly graded roofing battens should be treated as secure footholds during slating and tiling. Ungraded or part-graded timber should not be relied on in the same way.
Counter battens are different
A counter batten is not the same component as the horizontal batten carrying the tiles or slates. NFRC states that counter battens do not need BS 5534 grading when they are fully supported and fit for their intended use. See What Are Counter Battens on a Roof?.
For section choice and gauge, read the Roof Batten Sizes & Spacing Guide, or browse the Roofing Battens collection.
