Centre-to-centre (c/c) is the distance measured from the middle (centre) of one structural element to the middle of the next. It is the standard measurement in construction for the spacing of rafters, studs, battens, purlins, and other repeating elements.
Why centre-to-centre?
When you measure the distance between two beams, you can measure from edge to edge (the free space between them) or from centre to centre. In construction, c/c is the standard because:
1. Sheet materials fit — Standard boards (plasterboard, insulation, OSB) are 60 or 120 cm wide. At 60 cm c/c, each board fits exactly on three battens.
2. Insulation fits — Insulation boards are designed for 60 cm c/c (they are 58-59 cm wide and friction-fit between the battens).
3. Easy to set out — You always measure the same distance, regardless of the width of the element.
Standard c/c spacings
| Element | Standard c/c |
|---|---|
| Studs (timber frame) | 60 cm |
| Battens (internal wall) | 60 cm |
| Rafters | 60 cm |
| Purlins | 60-100 cm |
| Trusses | 80-120 cm |
| Deck joists | 40-50 cm |
| Gutter brackets | 60-80 cm |
How do you measure c/c?
1. Place first element — Set a stud in position
2. Measure 60 cm — From the centre of the first stud
3. Next element — The centre of the next stud is at 60 cm
4. Repeat — Always 60 cm from the previous cen
tre
> Note: The free space between two studs of 45 mm wide at 60 cm c/c is 60 – 4.5 = 55.5 cm (not 60 cm). This is exactly the width of standard insulation boa
rds.
Related terms
- Battens / framing
- Rafter
- Timber frame construction
- Truss
- Purlins