Basic Constructions for home DIY

Historical background

Wood is one of man’s most widely used raw materials. Such is the great variety of purposes for which wood can be used that, over a long period of time, many quite separate crafts evolved. These divisions of woodworking developed largely according to the nature of the end product. Because of new materials, new ideas, new technologies and changes in social life or customs some of these crafts, which were still thriving at the beginning of the century, have all but passed into history. Carriage and cart building, wheel-making and coopering are three where great difficulty would be experienced in finding a practising craftsman. Yet more wood is now being used than ever before, and through good ‘harvesting’, re-planting and conservation the supply will continue to meet demand.

Revival of interest has in some cases led to a resurgence of craftsmanship in many areas of woodworking. Marquetry, carving, musical instruments, toy-making, turnery and boatbuilding again are thriving activities. Indeed, in small boatbuilding the pendulum of favour has now swung back towards using wood for this most traditional of crafts.

Principal crafts

Despite the many branches of woodworking, the three major ones have always been, and still are, carpentry, joinery and furniture-making. It is true that the nature of the work done under these headings changes as time goes by. For instance, the amount of solid wood used in furniture making has decreased while the amount of chipboard continues to be on the increase. This means a change, or for many an extension, in the skills needed for the craft as the techniques required for the wise use of a different material are learned and mastered.

Carpentry

Carpentry is often thought of as rough work, with only limited skills. This may be true of some individuals but is more likely not to be so. Carpentry does frequently involve using wood ‘in the rough’ meaning timber straight from the saw and in situations where to plane it would be a waste of time and money. Floors and roofs are two of the main parts of a building where the work is classed as carpentry. Even on a building where floors and roofs are no longer of timber it is still very probable that the carpenter has played a significant part.

Floors of concrete, and roofs and stairs of the same material, need temporary moulds or supports for the concrete in its wet state. Wood is used far more than any other material for this purpose and this is an area of carpentry which has been growing in recent years. This temporary supporting of concrete work is known as shuttering or formwork; it has indeed almost become a sub-branch of carpentry.

In building work, many interior walls which are non-load-bearing are often referred to as partition walls. Frequently these are made of timber in the form of a framing, known as ‘studded partitions’. The stud is the vertical member of this framework. Vertical timbers are positioned at 406 mm centres, as are floor and ceiling joists, because the usual method of cladding such a partition is by plaster board which is nailed to the studding and then ‘skimmed1 with plaster. Plaster board, and other sheet materials such as plywood, hardwood, wall and insulation board, all have a standard width of 1220 mm. Joints, therefore, coincide with centres of the supporting timbers without cutting and waste. Joints in common use for this work are also shown. Trenches, both through and stopped, are frequently used, as are half-laps of one type or another. A simple joint much used on roofing work of traditional nature is a notch cut on an angle to suit the slope of the roof. It is employed where a rafter crosses the wall plate and is called a bird’s mouth. Many of the members are nailed together from the side. Joinery

Joinery work includes making and fitting doors, windows, staircases and the fitting out of a building to its purpose, e.g. the fitting of counters in a bank and shelves in a library.

Joiners nearly always work with ‘prepared’ timber, also known as planed, dressed or wrot. Joinery is invariably visible and therefore would go through a finishing process. The most common finish for joinery is paint, although hardwood joinery is more often varnished or polished.

Sometimes a craftsman may be described as a carpenter and joiner. This is common in building work where the joinery is usually of softwood. The most common softwood used is red deal, also called redwood. It is sometimes referred to by its country of origin, hence names like Baltic red, Scandinavian or Russian redwood. As with all timbers the quality varies but the best is selected for joinery and is often called joinery quality or joinery redwood.

Other softwoods used by the joiner include whitewood, hemlock and Columbian pine. The joiner may find himself using the same range of hardwoods used by the furniture industry, and here the range is very wide. Teak, iroko, mahogany, walnut and oak are some of the long established hardwoods to be seen alongside those of more recent introduction.

In a better class product the joints would be through mortise and tenons. Many doors, however, are imported and these frequently are of dowelled construction. This method, properly applied with sound materials and adhesives, is quite satisfactory for domestic-class doors.

Joggles, or horns, are left on for two reasons. The first is that it is wise to leave on some waste when a mortise is being cut near the end. This reduces the risk of the wood splitting at this point, especially if the joint is secured by wedging. The second reason, which applies to all doors whatever the pattern or mode of construction, is that the joggle projecting at a corner protects the door from damage during storage and transporting and before being hung.

Windows are made in almost every conceivable size and pattern, in both softwood and hardwood. Although many windows are mass produced to comply with British Standards specifications governing window sizes, materials and construction, a high proportion of windows outside the area of housing are ‘specials’ of one sort or another. This is also an example of framed construction.

Fairly large joggles are left on the head and sill of a window frame. They are used for ‘building-in’ purposes but they also protect the joinery during handling and transportation.

The usual practice on domestic type buildings is for the windows to be positioned into the brickwork as the wall is built. The sill joggles are usually notched to fit around the wall while the head joggles are sawn on the splay so as to allow the projecting part to be built in the wall. Exterior door frames have similar joggles and, while building practices regarding building-in sills vary a little, sides of frames are fixed in masonry joints by hoop-iron or similar cramps screwed to the frames. This is known as the ledged and braced door. Smaller and cheaper ones are made without the diagonal braces and are called braced doors. While the braces add a great deal to the rigidity of the door this also means that the door becomes ‘handed’ because, in order to gain full benefit from the braces, these members must slope upwards from the hanging side. This door is also an example of a construction which does not fit into any of the three main types of classification discussed later, although it can be thought of as a fore-runner to the frame.

Ledged and braced doors are a good example of construction which relies almost entirely on nailing. Usually, oval nails are chosen which will penetrate the battens by about 13 mm. The nails are driven in from the front and punched well home then the projecting points are hammered flat on the battens. Punching down on the end of the nails ensure that they are slightly below the surface. For extra strength ends of the ledges are often secured by a couple of screws. The braces can have a simple notching arrangement as shown, or merely be butted against the ledges.

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