Timber frame stud spacing, sheathing and restraint straps
Lateral restraint straps are fixed at a maximum of 2 m centres at floor and roof level and must be turned down against the inner face of the masonry and fixed over at least three joists or rafters with noggings. Studs are normally at 600 mm or 400 mm centres to suit the panel design and the sheathing fixing schedule.
The figures on one page
| Item | Limit | Figure |
|---|---|---|
| Lateral restraint strap spacing at floor and roof levelStraps at floor and ceiling level, carried over at least three joists with solid noggins | Maximum | 2 m |
| Cavity barriers at timber frame panel junctionsBarriers tight to both faces of the cavity, fixed and continuous | Maximum | At every compartment junction and opening edge |
| Breather membrane lap on a timber frameHorizontal laps shingled downwards; vertical laps over a stud, taped where the manufacturer requires it | Minimum | 100 mm |
| Clear cavity behind the breather membrane in timber frameClear residual width, measured from the face of the breather membrane to the back of the outer leaf | Minimum | 50 mm |
| DPC and DPM Lapping in Timber Frame | Minimum | 100 mm |
| Low-Level Protection for Timber Frame and SIPsFor closed panel timber frame and structural insulated panels (SIPs), the lowest timber element must be positioned at a minimum of 150mm above the finished ground level | Minimum | 150 mm |
| Sole plate DPC height in a timber frame wallMeasured from finished external ground or paving level to the underside of the sole plate DPC | Minimum | 150 mm |
| Specification and fixing of lateral restraint strapsLateral restraint straps must conform to design specifications for length, size (typically 30mm x 5mm), and corrosion protection | Minimum | 30 mm |
| Timber Sole Plate Height Above GroundThe lowest timber elements of a building, such as sole plates, should be positioned a minimum of 150mm above the finished ground level | Minimum | 150 mm |
| Wall tie spacing to a timber frameTies screwed into studs, not sheathing alone; closer spacing at reveals and movement joints | Maximum | Max 600 mm horizontally (at stud centres) and 450 mm vertically |
What this means on site
Straps are one of the few items that cannot be corrected later without opening up finished work, which is why they are a standard risk-based inspection item.
Sheathing fixings are a design item, not a site decision: the nail type, spacing at panel edges and spacing in the field all come from the frame designer’s schedule.
What actually gets picked up
- Straps at more than 2 m centres, or fixed over fewer than three joists.
- No noggings under the strap, so it flexes rather than restraining the wall.
- Straps not turned down, or turned down onto the outer leaf instead of the inner.
- Sheathing nails overdriven through the board face, losing their shear value.
Questions we get asked
- How far apart are lateral restraint straps?
- A maximum of 2 m centres at floor and roof level.
- What stud spacing is used in UK timber frame?
- Typically 600 mm centres, reduced to 400 mm where the panel design or loading requires it — always follow the frame designer’s schedule.
Where this is inspected
This is ProPlot's editorial summary of publicly available UK regulation and good practice. It is not building control approval or a warranty determination, and the designer's or manufacturer's tighter figure always takes precedence.