What stud spacing for a timber-frame wall: 400 or 600 mm?
In a timber-frame wall (platform framing), studs are placed at a constant on-centre spacing — measured from the axis of one stud to the axis of the next. In Polish workshop practice two values are used: 400 mm or 600 mm. This is not an arbitrary choice — both numbers follow from the module of the materials you screw to the frame.
Where exactly 400 and 600 mm come from
A standard sheathing panel — OSB or plasterboard — is 1200 mm wide. And here is the key arithmetic:
- 1200 = 3 × 400
- 1200 = 2 × 600
With both spacings the edge of every panel lands exactly on a stud axis. That means the joint between neighbouring panels has support underneath — there is something to screw both edges to, and the joint does not “float” in the air. The same module applies to insulation: mineral wool is produced in widths matched to 400 and 600 mm spacing, so it fits between the studs with a friction fit, without trimming along its whole length.
When 600 and when 400 mm
600 mm is the default spacing for typical single-family walls with structural sheathing. Fewer studs means less timber, lower cost and fewer thermal bridges (wood conducts heat worse than masonry, but still better than the insulation between the studs).
400 mm is used when the load grows or the sheathing gets thinner:
- a load-bearing wall under a long-span floor,
- lower storeys of taller buildings, where the load from above accumulates,
- heavy exterior cladding,
- thinner sheathing that needs closer support so it does not sag.
This is the Polish equivalent of the American 16″ and 24″ o.c. (on center) practice, i.e. 406 and 610 mm — the same two modules, in inches.
Why not “something in between”
Setting studs at, say, 500 mm looks innocent but breaks the whole module. Panel edges stop landing on stud axes, so every panel has to be trimmed, and the joints end up in random places without support. The result: more waste, more work, a weaker sheathing joint. That is why in practice you stick to the two values and do not improvise.
How Oczep.pl applies this
The Oczep.pl editor allows only 400 or 600 mm spacing — other values are blocked as an error before you get to order material. This way the module of the sheathing panels and insulation lines up from the first click, and the cut optimizer computes cuts on full panels, not on leftovers.
Create a free accountSources and disclaimers
The values 400 and 600 mm are established workshop practice in timber-frame construction, following from the 1200 mm module of sheathing panels (OSB, plasterboard) and the commercial widths of mineral wool. The choice between 400 and 600 mm for a specific load-bearing wall depends on the load and should follow from the design — a structural engineer decides on tighter spacing under heavy loads.