Battens 2 1/2" wide on walls from 8 to 16 ft, with a batten at each end. Each column aims for a different space between battens; the count is whichever comes closest while keeping every space equal.
| Wall | Aim 12" | Aim 16" | Aim 20" |
|---|---|---|---|
| 8 ft | 7 battens13 1/16" | 6 battens16 3/16" | 5 battens20 7/8" |
| 10 ft | 9 battens12 3/16" | 7 battens17 1/16" | 6 battens21" |
| 12 ft | 11 battens11 5/8" | 9 battens15 3/16" | 7 battens21 1/16" |
| 14 ft | 12 battens12 9/16" | 10 battens15 7/8" | 8 battens21 1/8" |
| 16 ft | 14 battens12 1/16" | 11 battens16 7/16" | 9 battens21 3/16" |
Spaces are the clear gap between battens, not center to center. Open a wall to change the batten width or add grid rows.