Laying Out.
In order to afford the student a clear idea of what is meant by laying out on the floor, an example of a simple close-string stair is given. In [Fig. 33], the letter F shows the floor line; L is the landing or platform; and W is the wall line. The stair is to be 4 feet wide over strings; the landing, 4 feet wide; the height from floor to landing, 7 feet; and the run from start to finish of the stair, 8 feet 8½ inches.
The first thing to determine is the dimensions of the treads and risers. The wider the tread, the lower must be the riser, as stated before. No definite dimensions for treads and risers can be given, as the steps have to be arranged to meet the various difficulties that may occur in the working out of the construction; but a common rule is this: Make the width of the tread, plus twice the rise, equal to 24 inches. This will give, for an 8-inch tread, an 8-inch rise; for a 9-inch tread, a 7½-inch rise; for a 10-inch tread, a 7-inch rise, and so on. Having the height (7 feet) and the run of the flight (8 feet 8½-inches), take a rod about one inch square, and mark on it the height from floor to landing (7 feet), and the length of the going or run of the flight (8 feet 8½ inches). Consider now what are the dimensions which can be given to the treads and risers, remembering that there will be one more riser than the number of treads. Mark off on the rod the landing, forming the last tread. If twelve risers are desired, divide the height (namely, 7 feet) by 12, which gives 7 inches as the rise of each step. Then divide the run (namely, 8 feet 8½ inches) by 11, and the width of the tread is found to be 9½ inches.
Great care must be taken in making the pitch-board for marking off the treads and risers on the string. The pitch-board may be made from dry hardwood about ⅜-inch thick. One end and one side must be perfectly square to each other; on the one, the width of the tread is set off, and on the other the height of the riser. Connect the two points thus obtained, and saw the wood on this line. The addition of a gauge-piece along the longest side of the triangular piece, completes the pitch-board, as was illustrated in [Fig. 15].
The length of the wall and outer string can be ascertained by means of the pitch-board. One side and one edge of the wall string must be squared; but the outer string must be trued all round. On the strings, mark the positions of the treads and risers by using the pitch-board as already explained ([Fig. 17]). Strings are usually made 11 inches wide, but may be made 12½ inches wide if necessary for strength.
Fig. 33. Method of Laying Out a Simple, Close-String Stair.
After the widths of risers and treads have been determined, and the string is ready to lay out, apply the pitch-board, marking the first riser about 9 inches from the end; and number each step in succession. The thickness of the treads and risers can be drawn by using thin strips of hardwood made the width of the housing required. Now allow for the wedges under the treads and behind the risers, and thus find the exact width of the housing, which should be about ⅝-inch deep; the treads and risers will require to be made 1¼ inches longer than shown in the plan, to allow for the housings at both ends.
Before putting the stair together, be sure that it can be taken into the house and put in position without trouble. If for any reason it cannot be put in after being put together, then the parts must be assembled, wedged, and glued up at the spot.
It is essential in laying out a plan on the floor, that the exact positions of the first and last risers be ascertained, and the height of the story wherein the stair is to be placed. Then draw a plan of the hall or other room in which the stairs will be located, including surrounding or adjoining parts of the room to the extent of ten or twelve feet from the place assigned for the foot of the stair. All the doorways, branching passages, or windows which can possibly come in contact with the stair from its commencement to its expected termination or landing, must be noted. The sketch must necessarily include a portion of the entrance hall in one part, and of the lobby or landing in another, and on it must be laid out all the lines of the stair from the first to the last riser.
The height of the story must next be exactly determined and taken on the rod; then, assuming a height of risers suitable to the place, a trial is made by division in the manner previously explained, to ascertain how often this height is contained in the height of the story. The quotient, if there is no remainder, will be the number of risers required. Should there be a remainder on the first division, the operation is reversed, the number of inches in the height being made the dividend and the before-found quotient the divisor; and the operation of reduction by division is carried on till the height of the riser is obtained to the thirty-second part of an inch. These heights are then set off as exactly as possible on the story rod, as shown in [Fig. 33].
The next operation is to show the risers on the sketch. This the workman will find no trouble in arranging, and no arbitrary rule can be given.
A part of the foregoing may appear to be repetition; but it is not, for it must be remembered that scarcely any two flights of stairs are alike in run, rise, or pitch, and any departure in any one dimension from these conditions leads to a new series of dimensions that must be dealt with independently. The principle laid down, however, applies to all straight flights of stairs; and the student who has followed closely and retained the pith of what has been said, will, if he has a fair knowledge of the use of tools, be fairly equipped for laying out and constructing a plain, straight stair with a straight rail.
Plain stairs may have one platform, or several; and they may turn to the right or to the left, or, rising from a platform or landing, may run in an opposite direction from their starting point.
When two flights are necessary for a story, it is desirable that each flight should consist of the same number of steps; but this, of course, will depend on the form of the staircase, the situation and height of doors, and other obstacles to be passed under or over, as the case may be.
In [Fig. 32], a stair is shown with a single platform or landing and three newels. The first part of this stair corresponds, in number of risers, with the stair shown in [Fig. 33]; the second newel runs down to the floor, and helps to sustain the landing. This newel may simply be a 4 by 4-inch post, or the whole space may be inclosed with the spandrel of the stair. The second flight starts from the platform just as the first flight starts from the lower floor, and both flights may be attached to the newels in the manner shown in [Fig. 29]. The bottom tread in [Fig. 32] is rounded off against the square of the newel post; but this cannot well be if the stairs start from the landing, as the tread would project too far onto the platform. Sometimes, in high-class stairs, provision is made for the first tread to project well onto the landing.
If there are more platforms than one, the principles of construction will be the same; so that whenever the student grasps the full conditions governing the construction of a single-platform stair, he will be prepared to lay out and construct the body of any stair having one or more landings. The method of laying out, making, and setting up a hand-rail will be described later.
Stairs formed with treads each of equal width at both ends, are named straight flights; but stairs having treads wider at one end than the other are known by various names, as winding stairs, dog-legged stairs, circular stairs, or elliptical stairs. A tread with parallel sides, having the same width at each end, is called a flyer; while one having one wide end and one narrow, is called a winder. These terms will often be made use of in what follows.
The elevation and plan of the stair shown in [Fig. 34] may be called a dog-legged stair with three winders and six flyers. The flyers, however, may be extended to any number. The housed strings to receive the winders are shown. These strings show exactly the manner of construction. The shorter string, in the corner from 1 to 4, which is shown in the plan to contain the housing of the first winder and half of the second, is put up first, the treads being leveled by aid of a spirit level; and the longer upper string is put in place afterwards, butting snugly against the lower string in the corner. It is then fastened firmly to the wall. The winders are cut snugly around the newel post, and well nailed. Their risers will stand one above another on the post; and the straight string above the winders will enter the post on a line with the top edge of the uppermost winder.
Fig. 34. Elevation and Plan of Dog-Legged Stair
with Three Winders and Six Flyers.
Platform stairs are often constructed so that one flight will run in a direction opposite to that of the other flight, as shown in [Fig.35]. In cases of this kind, the landing or platform requires to have a length more than double that of the treads, in order that both flights may have the same width. Sometimes, however, and for various reasons, the upper flight is made a little narrower than the lower; but this expedient should be avoided whenever possible, as its adoption unbalances the stairs. In the example before us, eleven treads, not including the landing, run in one direction; while four treads, including the landing, run in the opposite direction; or, as workmen put it, the stair “returns on itself.” The elevation shown in [Fig. 36] illustrates the manner in which the work is executed. The various parts are shown as follows:
Fig. 35. Plan of Platform Stair Returning on Itself.
[Fig. 37] is a section of the top landing, with baluster and rail.
[Fig. 38] is part of the long newel, showing mortises for the strings.
Fig. 36. Elevation Showing Construction of Platform Stair
of which Plan is Given in [Fig. 35].
Fig. 37. Section
of Top Landing,
Baluster, and Rail.
[Fig. 39] represents part of the bottom newel, showing the string, moulding on the outside, and cap.
[Fig. 40] is a section of the top string enlarged.
[Fig. 41] is the newel at the bottom, as cut out to receive bottom step. It must be remembered that there is a cove under each tread. This may be nailed in after the stairs are put together, and it adds greatly to the appearance.
We may state that stairs should have carriage pieces fixed from floor to floor, under the stairs, to support them. These may be notched under the steps; or rough brackets may be nailed to the side of the carriage, and carried under each riser and tread.
There is also a framed spandrel which helps materially to carry the weight, makes a sound job, and adds greatly to the appearance. This spandrel may be made of 1¼-inch material, with panels and mouldings on the front side, as shown in [Fig. 36]. The joint between the top and bottom rails of the spandrel at the angle, should be made as shown in [Fig. 42] with a cross-tongue, and glued and fastened with long screws. [Fig. 43] is simply one of the panels showing the miters on the moulding and the shape of the sections. As there is a convenient space under the landing, it is commonly used for a closet.
Fig. 38. String Mortises in Long Newel.
Fig. 39. Mortises in Lower Newel for String,
Outside Moulding, and Cap.
Fig. 40. Enlarged Section of Top String.
Fig. 41. Newel Cut to
Receive Bottom Step.
In setting out stairs, not only the proportions of treads and risers must be considered, but also the material available. As this material runs, as a rule, in certain sizes, it is best to work so as to conform to it as nearly as possible. In ordinary stairs, 11 by 1-inch common stock is used for strings and treads, and 7-inch by ¾-inch stock for risers; in stairs of a better class, wider and thicker material may be used. The rails are set at various heights; 2 feet 8 inches may be taken as an average height on the stairs, and 3 feet 1 inch on landings, with two balusters to each step.
In [Fig. 36], all the newels and balusters are shown square; but it is much better, and is the more common practice, to have them turned, as this gives the stairs a much more artistic appearance. The spandrel under the string of the stairway shows a style in which many stairs are finished in hallways and other similar places. Plaster is sometimes used instead of the panel work, but is not nearly so good as woodwork. The door under the landing may open into a closet, or may lead to a cellarway, or through to some other room.
In stairs with winders, the width of a winder should, if possible, be nearly the width of the regular tread, at a distance of 14 inches from the narrow end, so that the length of the step in walking up or down the stairs may not be interrupted; and for this reason and several others, it is always best to have three winders only in each quarter-turn. Above all, avoid a four-winder turn, as this makes a breakneck stair, which is more difficult to construct and inconvenient to use.
Fig. 42. Showing Method of Joining Spandrel Rails,
with Cross-Tongue Glued and Screwed.
Fig. 43. Panel in Spandrel, Showing Miters on Moulding,
and Shape of Section.
Bullnose Tread. No other stair, perhaps, looks so well at the starting point as one having a bullnose step. In [Fig. 44] are shown a plan and elevation of a flight of stairs having a bullnose tread. The method of obtaining the lines and setting out the body of the stairs, is the same as has already been explained for other stairs, with the exception of the first two steps, which are made with circular ends, as shown in the plan. These circular ends are worked out as hereafter described, and are attached to the newel and string as shown. The example shows an open, cut string with brackets. The spandrel under the string contains short panels, and makes a very handsome finish. The newels and balusters in this case are turned, and the latter have cutwork panels between them.
Fig. 44. Elevation and Plan of Stair with Bullnose Tread.
Fig. 45. Section
through
Bullnose Step.
Bullnose steps are usually built up with a three-piece block, as shown in [Fig. 45], which is a section through the step indicating the blocks, tread, and riser.
[Fig. 46] is a plan showing how the veneer of the riser is prepared before being bent into position. The block A indicates a wedge which is glued and driven home after the veneer is put in place. This tightens up the work and makes it sound and clear. [Figs. 47 and 48] show other methods of forming bullnose steps.
Fig. 46. Plan Showing Preparation of Veneer
before Bending into Position.
[Fig. 49] is the side elevation of an open-string stair with bullnose steps at the bottom; while [Fig. 50] is a view showing the lower end of the string, and the manner in which it is prepared for fixing to the blocks of the step. [Fig. 51] is a section through the string, showing the bracket, cove, and projection of tread over same.
Fig. 47.Fig. 48.
Methods of Forming Bullnose Steps.
Fig. 49. Side Elevation of
Open-String Stair with
Bullnose Steps.
Figs. [52] and [53] show respectively a plan and vertical section of the bottom part of the stair. The blocks are shown at the ends of the steps ([Fig. 53]), with the veneered parts of the risers going round them; also the position where the string is fixed to the blocks ([Fig. 52]); and the tenon of the newel is marked on the upper step. The section ([Fig. 53]) shows the manner in which the blocks are built up and the newel tenoned into them.
The newel, [Fig. 49], is rather an elaborate affair, being carved at the base and on the body, and having a carved rosette planted in a small, sunken panel on three sides, the rail butting against the fourth side.