Roof Spacing / Colorbond Sheeting
The Batten Spacing Colorbond Roofs Need
Most people looking up batten spacing Colorbond roof guides want a single number. The honest answer is a short table instead. Specifically, spans depend on the sheet profile, its thickness, the wind classification and where the span sits. So here is how to read all four.
SEC 01 / Manufacturer tables
Manufacturer recommendations for spacing
The sheeting maker publishes maximum support spacings for every profile and thickness. So that table is the starting point, always.
For example, take the classic corrugated profile in 0.42mm base metal thickness. Published design data lists a 700mm maximum for a single span, 900mm for end spans and 1200mm for internal spans. However, those figures hold under the publisher’s stated wind model, with supports of at least 1.0mm BMT. Meanwhile, step up to 0.48mm sheet and the allowable spans grow. The pattern to memorise is the end span rule. The first and last bays of every sheet run are held tighter than the middle.
Same roof, two limits. End spans tighter, internal spans wider, straight from the published table.
SEC 02 / Wind rating
Factoring in wind rating in Adelaide regions
Every site carries a wind classification under AS 4055, from N1 up to N6 in non cyclonic areas. Also, published spacing tables are only valid within their stated wind assumptions. For instance, much of the Adelaide plain sits in the lower N classes. In contrast, exposed coastal edges, ridge lines in the hills and open rural sites climb higher. As a result, a higher class means tighter spacings, more fasteners per sheet, or both. The classification, of course, comes from the certifier, engineer or council paperwork. It is never guessed from the street.
SEC 03 / Roof pitch
How roof pitch affects spacing
Pitch mostly decides which profile you are allowed to use, and the profile then brings its own table. For example, traditional corrugated sheet needs about 5 degrees of fall to shed water reliably. Trapezoidal and concealed fix profiles, however, are rated to shallower pitches in their own literature. So the batten spacing Colorbond roof sheets need does not swing much with pitch directly. Instead, what pitch changes is the profile choice, and the profile changes the spans. Still, the one extra to watch on low pitches is water load and overlap detailing. The profile’s guide also covers both, alongside its spans.
SEC 04 / Sheet profiles
Sheet profile considerations
Rib height is stiffness. A 16mm corrugation, a taller trapezoidal rib and a deep concealed fix pan all span differently in the same thickness. As a result, every profile carries its own table. It is also why numbers never transfer between profiles. Besides, the sheet is only half the check: the battens underneath have their own span and screw pull out tables. Our steel roof battens publish capacity data for the 40mm top hat at the standard spans, in two thicknesses. So both layers of the roof can be checked against the same wind figure.
Two tables, one roof.
First, read the sheet’s maximum support spacing for the profile, thickness and wind class. Then confirm the batten section and its fixings carry that same load, at the truss spacing on the drawings. Finally, the lower limit governs. In short, that is the entire method behind the batten spacing Colorbond roof projects get signed off on.
Batten spans checked against your sheet
First, send the profile, sheet thickness, wind classification and truss centres. Then we size the 40mm top hat against the load, quote within one business day and despatch across SA.
COLORBOND®, ZINCALUME®, LYSAGHT®, CUSTOM ORB® and TOPSPAN® are registered trade marks of BlueScope Steel Limited. Kspan is an independent Adelaide fabricator, and is not affiliated with BlueScope. Example figures are quoted from published Lysaght design literature, under its stated assumptions. However, they change with wind class, support thickness and product updates. So always work from the current tables for your exact sheet and site, with the project engineer’s sign off.
