Roof materials
Roof battens
Batten rows and stock lengths from entered slope length, gauge and roof width.
How to use this calculator
Prepare measurements and product data
Enter roof width, slope length, verified gauge and batten stock length in metres. Enter 40 cm as 0.4 m. Roofing instructions establish eaves and ridge fixed points; use this tool for a preliminary quantity rather than locating those points.
Formula and rounding
Model rows = round up(slope length / gauge). Planned length = rows × width × (1 + allowance / 100). Stock pieces = round up(planned length / stock length).
Worked example
Model example: 10 m width, 4.8 m slope length, entered 0.4 m gauge, 10% allowance and 4 m stock lengths. Gauge is not an installation recommendation.
| Stage | Calculation |
|---|---|
| Model rows | 4.8 / 0.4 = 12 |
| Base length | 12 × 10 = 120 m |
| Plan with allowance | 120 × 1.10 = 132 m |
| Stock lengths | 132 / 4 = 33 pieces → 132 m |
The model gives 33 stock lengths. It does not establish that these will make every required row: supported joints, cuts and extra battens need a separate check.
Check before buying
- All four lengths use metres.
- Gauge comes from the selected roofing instructions and lies within its permitted range.
- Fixed points, extra rows and joint locations have been set out.
Limitations
Rows = ceil(length / gauge) is a quantity simplification. It is neither an interval count nor complete setting out. Eaves/ridge battens, counterbattens and fixings are not automatically added. Dividing total length by stock length does not optimize cuts or select timber section.
Questions and answers
Do 12 rows mean 12 intervals?
No. Twelve lines have 11 intervening intervals. This tool estimates a simplified row count; establish the complete arrangement and fixed points from product instructions.
Why can total stock length be insufficient?
Pieces must suit individual rows and joint positions. An offcut from one piece may not be usable in another row. Prepare a cutting list before buying.
Sources and scope
- Marley — Roofing Sitework Guide, batten gauge, pp. 60–61
Product-specific setting out between eaves/ridge battens and separate fixed points. The simple quantity calculator is not that setting-out method.
- NIST — SI Units: Length
Length units and the exact inch-to-millimetre relationship. The measuring workflow below is our own practical procedure.
Tile documentation explains gauge and fixed eaves and ridge points for a particular system. It does not establish a universal 0.4 m gauge. The illustrated 12 rows and 33 stock lengths follow our simplified quantity model. NIST supports length units; it does not select gauge, timber section or batten joint details.