Short answer. Batten spacing depends not on “profiled sheeting” in general but on the wave height of the specific profile: the higher the wave, the wider the battens can sit. For T20r that is roughly 0.5 m, for T35 about 1 m, for T57 wider still. The exact figure comes from a structural designer working to your snow load, and below we explain why we will not name it for you.
Data for our profiles
This is the part we can state precisely: profile geometry and the minimum roof pitch below which the sheet must not be laid, whatever the battens.
| Profile | Wave height | Minimum roof pitch | Working width |
|---|---|---|---|
| T10 | 10 mm | not for roofing | 1,155 mm |
| T20f | 20 mm | not for roofing | 1,100 mm |
| T20r | 20 mm | from 12° | 1,100 mm |
| T35 | 35 mm | from 9° | 1,080 mm |
| T45 | 45 mm | from 8° | 1,020 mm |
| T57 | 57 mm | from 6° | 960 mm |
| Classic | 20 mm, 350 mm pitch | from 14° | 1,100 mm |
T10 and T20f are wall profiles. Battens under them are worked out differently, because the load is wind rather than snow, and they are not laid on roofs.
How much timber a roof slope takes
The arithmetic is simple: number of rows = slope width divided by spacing, plus one; the length of each row is the length along the ridge. For a 4 × 6 m slope it looks like this.
| Batten spacing | Rows | Linear metres of timber |
|---|---|---|
| 0.5 m | 9 | 54 m |
| 0.8 m | 6 | 36 m |
| 1.0 m | 5 | 30 m |
| 1.5 m | 3 | 18 m |
The difference between 0.5 and 1.0 m is 24 linear metres of timber on a single slope. That is why a profile with a higher wave often pays for itself on the battens, even when the sheet itself costs more.
Why we will not name the spacing for you
Batten spacing is set by three things at once: wave height, steel thickness and the snow load where you are. We know the first two — they are in the table above. We do not know the third and will not guess: an error here is paid for with collapsed sheets after the first serious winter.
The figures circulating online are typical values for moderate snow and 0.45-0.50 mm steel. They are not a standard. If the roof is complex or the area is snowy, the spacing has to come from a design, not from an article.
What a cut-to-length sheet changes
A standard sheet rarely matches the slope length, so the roof is assembled from two rows with a horizontal overlap. Every such overlap needs its own row of battens, otherwise the joint sags.
We roll the sheet to the full slope length. There is no horizontal joint at all, which means no extra row of timber under it and no place where water sits in an overlap. On a 6-metre slope that is one row of battens less and one potential leak less.
How to order
Step 1. Measure the slope
Length from ridge to eaves and width along the ridge. Add the pitch angle if you know it — we use it to rule out profiles that must not go on such a roof.
Step 2. Tell us your batten spacing
If the battens are already up, give us the spacing and the manager will say which of our profiles will sit on them. If not, choose the profile first and set the battens to it.
Step 3. Order the sheet to the slope length
Call (067) 077-56-77, Mon-Fri 08:00-17:00. Production 1-2 days, delivery a further 1-5 days.
What we do not do
We do not design roofs and we do not calculate snow loads. We do not sell timber and we do not fit battens. We give you the profile geometry, the minimum pitch and sheets of the length you need — the rest is you or your designer.
FAQ
Can profiled sheeting go on solid decking? It can, and on complex roofs it does. But a ventilation gap between the sheet and the decking is required, otherwise condensation never dries.
What timber should I use? Most often 50×50 mm or a 100×25 mm board. The section depends on spacing and load — again a question for the design, not for us.
Does steel thickness affect the spacing? Yes. 0.50 mm spans further than 0.45 mm. We roll 0.40-0.70 mm and you choose the thickness with the order.
What is the maximum sheet length? You set the length with the order. The manager will tell you the practical limit for your project — it is set by transport and by getting the sheet onto the roof, not by the line.
What if my pitch is below the figure in the table? Then that profile is not suitable — take one with a higher wave. T57 works from 6°, the lowest threshold in our range.