Wall linings were typically plasterboard or fibrous plaster sheet and finished with wallpaper. Hardboard and fibrous plaster sheet were also sometimes used, and tongue-and-groove timber was used in some circumstances.
Stud heights were between 9’–10’ 6” (2.7–3.15 m) although they could be 11’ (3.3 m) in large houses.
Manufacture of plasterboard in New Zealand began in 1925 – before then it was imported from Canada. Once local production commmenced, it quickly became the preferred interior wall lining for all houses. It was easy to install and the surface could be stopped to create a smooth, flush finish to which wallpaper could be applied directly.
Plasterboard was originally developed as a rigid backing board for stucco, and architectural drawings indicate that many of the 1930s stucco-clad houses have plasterboard as the stucco substrate.
Gibraltar board was available in a sheet sizes of 6 x 3’ (1.800 x 900 mm) and 3/8” thick (9.5 mm).
Although generally stopped to give a flush finish, where plasterboard was used in service rooms, as a cheaper and simpler alternative, it was sometimes finished by covering joints with half round beading.
An early type of hardboard was first made in England in 1898. In the 1920s, William Mason developed a method of compressing waste wood pulp to create a hard, durable, low-cost sheet material called Masonite, that could be used as a lining on its own that could be painted or as a substrate for other finishes.
A further development was to temper the hardboard. Tempering involved coating one side of the sheets with linseed oil, then baking to a high temperature. This made the board harder and more rigid, with a finish that had greater resistance to water, making it very suitable as a wet area wall lining.
Masonite or hardboard sheets were available in sheet sizes that were typically 8 x 4’ (2.4 m x 1.2 m) and a range of thicknesses including 1/16” (1.5 mm), 1/8” (3 mm) and ¼” (6 mm). For use as a wall lining, the hardboard sheet thickness was generally ¼” (6 mm). Joints were covered by half round beading.
Asbestos-cement sheets were sometimes used in service areas. They were hard, durable and water-resistant and could be stopped to create a smooth, flush finish that provided a suitable substrate for tiling or for painting.
Timber lining consisting of narrow, 4 x ½” (100 x 12 mm) tongue, grooved and veed (TG&V) boards was commonly used inside wardrobes and built-in cupboards, with a shellac finish. It was also used in ceilings of service areas with a shellac or paint finish.
Ceilings were lined with plasterboard or sometimes fibrous plaster. Joints were stopped to give a flush finish for painting.
The intersections between the wall and ceiling were covered with a timber or fibrous plaster cornice or scotia which may have a coved or flat profile. Ornate, patterned art deco design zig-zag or chevron motif scotias were often seen.
A central ceiling rose in a stylised pattern that included zig-zags and chevron motifs was a common feature of ceilings in the main rooms of the house such as living, dining and main bedrooms. It was not uncommon for several different cornice and/or ceiling designs to be used in one house.
The walls of the main living spaces were generally papered, as the quality of the plasterboard and stopping were not suitable for a high-quality paint finish.
Other areas lined with hardboard or asbestos-cement sheet were painted or tiled.
Match lining was generally shellaced or varnished.
Internal wall linings are unlikely to have been altered except where walls have been removed. However, they may have been replastered to provide a paint quality finish to the walls.
Service areas, in particular, bathrooms and laundries, are likely to have had the original hardboard or asbestos-cement lining removed and replaced with plasterboard or a wet area lining such as plastic laminate-finished wallboard.
Ceilings are likely to be original. In the rare situation where a ceiling has been replaced, it is only likely to have occurred where the original ceiling was in a poor condition. Ceiling damage is not uncommon, as roofs of art deco houses were prone to leaking.