This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol5", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
There are two general divisions in the native building woods of Australia - the gums and the pines, the gums being by far the greater in importance for building purposes. The great gum (eucalyptus) forests, "the Bush," cover the greater part of the continent, and the settlers have cut into these vastnesses to found their cities and build their settlements. Thus year by year the forests have been pressed back, and the materials from the mills have increased in price owing to heavier freights and handling charges.
The pines have but a limited output for building purposes, and, as the demand for this class of timber is considerable, large quantities are imported into the Commonwealth. The principal native pines are those found in Queensland, and known generally as Queensland pine, and the Murray pines from New South Wales. These are supplemented by the importation of Kauri pine from New Zealand, and by finishing woods from various parts of the world, the principal among which being red Californian pine, Baltic pine, American walnut, oak, ash, etc.
For structural timbers the native woods are largely used, the exception being in best class roof and wood-framing work, where imported Oregon is generally preferred.
The jarrah of Western Australia, a dark red heavy timber, is used both structurally and for finishing, and looks well when oiled or polished.
Hard wood is used for framing houses, ground-floor joists, and the cheaper class of roofs, etc. When carefully selected and dried it makes good flooring with an oaklike finish.
Red gum, a dense red wood somewhat like jarrah in appearance, is an excellent material for all purposes when sunk into the ground. It is therefore much used in the Eastern States for floor bearers, plates, stumps, and in fencing posts, etc.
The country produces a large variety of beautiful show woods for panelling and special joinery work, among which may be mentioned - blackwood, Huon pine, beamwood, silky oak, etc.
With these materials, highly skilled labour, and wealthy demand, excellent work in carpentry and joinery has been done in Australia, the practice as a whole proceeding much upon English lines.
A detail section is given in Fig. 237 of an ordinary wood villa building as used in Australia. The structure, if in Western Australia, would probably be all of Australian Constructional Methods - Plastering 193 jarrah; in other parts of Australia a. more general Specification would be as follows -
"All timber in or near ground, red gum.
"Stumps 4 feet 6 inches apart centres (these are sunk in ground to necessary depths, and have sole plates under). Along the top of the stumps all around outside of building is a 4 x 3-inch plate, the joists on inside of building being supported by the 5 x 3-inch bearer.
"Floor joists of 5 x 2-inch hard wood, 18-inch apart centres, receiving 6 x 1 1/8-inch T. & G. dry hard wood flooring. Hard-wood studs for walls, 18 inches apart centres, tenoned into top and bottom plates and diagonally braced outside, with 3 x 1-inch H.W. braces cut in. There is a 4 x 3-inch top-plate and joists and rafters, eaves, etc., as shown. Spouting of 22 gauge galvanised iron. The external faces lined with 6-inch feather edge weatherboards having 1 1/2-inch lap, finishing next ground on to 9 x 1-inch red gum plinth, and at all angles setting fair against 2 x 1 1/4-inch stops."
The detail given in Fig. 238 shows a verandah of the usual Australian type, where the main roof of the villa continues down to form the verandah roof, the whole being covered with French Marseilles tiles, copper wired on to deal battens. Oregon pine is generally used for rafters, spaced 18 inches apart centres, the under-side lining being of 4 by 1/2-inch tongued and grooved and V-jointed Kauri (New Zealand) pine boarding.
Posts may be, as also all other exposed woodwork, of redwood (American) or of jarrah.
Posts, 8 feet apart centres, dowelled with galvanised iron gas piping into hard bluestone curb, turned where shown with moulded and mitred caps, housed into brackets and frieze rail; the 9 by 3 inch-head to be continuous and forked through upper portion of posts and bolted. Square spindles stub-tenoned in. Fascia 8 by 1 inch beaded with batten lined soffit; spouting out of 22 gauge galvanised sheet iron secured with stout hoop iron straps riveted on. Floor of Australian made tiles from Mitchan, Victoria.
Shoring and Under-Pinning In a new country like Australia the architectural practice among old and dangerous structures is limited, the work lying rather with new buildings upon virgin sites. With alterations, however, the architect has often much to do, owing to the rapidly growing demands of business and commerce.
For shoring, Oregon (American) timber is generally used, being found best for this class of work. Of late years there has been a growing tendency to supplant timber needles with those of steel. Short lengths of rolled steel joists, taking up much less room and needing less cutting for their insertion through walls, present many advantages over the older method.
Much is also done by cutting out 4 1/2-inch thicknesses of walls, and rolling in horizontally laid steel joists, one by one, to take overhead weights (the working being from both sides of wall), afterwards cutting the required openings below. By this method shoring is altogether avoided if the old brickwork be strong in adhesive quality.