What is it?
Timber studs are sawn softwood sections used to form the structural frame of a partition or the lining to an opening, fixed vertically between a head plate and a sole plate. They serve the same role as metal studs, a frame for linings to fix to, but are cut from solid timber rather than cold-formed steel.
Around openings such as doors, a pair of studs (sometimes doubled up) forms the jamb either side of the frame, carrying the load from the lintel above down to the floor.
- 1Timber Stud
- 2Timber Nogging
What does it do?
Timber studs support the linings fixed to them (typically plasterboard) and, where doubled up around an opening, carry the load from a lintel down to the sole plate and floor structure below. The cavity between studs is used for insulation and for routing services (hiding the cabling and pipework in the wall).
Unlike a typical metal stud partition, a timber stud wall can more readily be built as a loadbearing structure, since timber sections resist compression well along their length.
Where is it used?
- Internal partition walls, particularly in traditional and residential construction
- Door and window jambs, framing the opening either side of the frame
- Loadbearing partitions supporting floors or roofs above
Types
Structural timber is graded by strength, most commonly C16 (general construction) and C24 (higher strength, used where greater loads or longer spans are involved). The correct grade depends on what the studs are carrying: a jamb supporting a lintel needs checking against the load it takes, not just sized by habit.
Typical sizes
Common stud sections are 38 × 89 mm and 38 × 140 mm, with studs typically spaced at 400 mm or 600 mm centres. Jamb studs around an opening are often doubled (two sections fixed together) to carry the concentrated load from the lintel.
How to specify
Specification starts with what the studs need to carry: a non-loadbearing partition just needs a section wide enough for the insulation and services it hides, while a jamb or loadbearing stud needs a Structural Engineer's sizing and grading (C16 or C24) against the actual load path.
Moisture content matters more for timber than for metal studs. Timber should be installed at the moisture content it will settle to in use, otherwise shrinkage can telegraph through the finished lining as cracking at joints.
Other considerations
Timber studs move more than metal with changes in moisture, which can show up as cracking at plasterboard joints if the timber wasn't adequately dried before fixing. Where fire performance matters, the studs themselves don't resist fire. That comes from the lining build-up, the same as with metal stud walls.
Interacting elements
- Plasterboard: fixed to the studs to form the wall or lining surface
- Insulation: fitted within the stud cavity
- Door frame: fixed to the jamb studs either side of the opening
- Sockets and switches: the cabling for these must be routed through drilled holes in the studs to conceal them behind the plasterboard.
- Sole and head plate: the timber runs the studs fix into top and bottom