SR54 Report on racking resistance of long sheathed timber framed walls with openings (1993)

This study forms the first phase of an investigation into the wind and earthquake racking resistance for timber-framed New Zealand houses from roof to ground floor level.

10 racking tests were conducted with five different long (up to 6.6 m) wall configurations, incorporating wall returns and typical openings and using various combinations of sheathings. No external uplift restraints were used. Generally, only standard nailing between the bottom plate and the foundation beam provided wall uplift restraint. However, in a few instances light steel end straps were also used. Additional gravity load was imposed in only one instance.

The measured strengths were compared to the summation of component panel strengths. The component panel behaviour was obtained using the theoretical response for panels with total uplift restraint (based on nail slip tests) and then the additional deformations due to predicted uplift (from BRANZ P21 tests where partial uplift restraint is applied) added.

The measurements presented also include uplift at wall corners and opening edges (panel deflected shapes), slip between sheathing and frame and panel shear strains. A detailed literature survey is given, and the results of small sample testing to determine nail load-slip characteristics presented.