Art deco homes typically used native timbers such as rimu or miro for wall framing, though other timbers such as beech or imported Western red cedar were occasionally used. See use of timber for detail.
The framing, consisting of studs and top and bottom plates, was 4 x 2” (100 x 50 mm) timber.
Single-storey external wall framing ran continuously from the top of the parapet to the bottom plate. Ceiling joists sat on a 6 x 1” (150 x 25 mm) ribbon board housed into the studs.
The bottom plate was fixed directly over the floor joists before the flooring was laid.
Studs were typically spaced at 18” (450 mm) centres and could be housed into the bottom plate to reduce the risk of the timber twisting (Figure 1).
Stud heights typically ranged between 9’ and 10’6” (2.7–3.15 m), although they could be 11’ (3.3 m) in large houses.
Dwangs were cut in between studs, typically to provide sheet fixing at 3’ (900 mm) centres, but this varied.
The top of the parapet wall was usually sloped inwards to direct water to the roof rather than the outside of the building and may not have been flashed originally.
Bracing for lateral stability was provided by 6 x 1” (150 x 25 mm) timber fixed at 45° to the studs and running from the top of the parapet to the bottom plate. Bracing boards were housed into each stud where they intersected and into the top and bottom plates (Figure 1).
The bracing strength of existing construction is often not known. What should be used in the bracing calculations required by building consent authorities when repairs or renovations are planned?
BRANZ tested a range of older bracing systems to provide wall bracing ratings. The results can be found in BRANZ Study Report SR305 Bracing ratings for non-proprietary bracing walls.
Loadbearing walls were the external walls and generally one or both of the internal walls on either side of the central hallway, but this was dependent on the floor plan and the roof configuration. Internal walls other than those parallel to the corridor were generally non-loadbearing.
Lintel sizes over door and window openings varied according to the opening spans, but are generally likely to be undersized by modern framing requirements.
Two-storey construction consisted of balloon framing using continuous full-height stud framing. A 6 x 1” (150 x 25 mm) ribbon board housed into studs supported the first-floor joists.