THE CONSTRUCTION OF VARIOUS PARTS OF STAIRS, SHOWING THE APPLICATION OF
THE STEEL SQUARE FOR SETTING OUT STRINGS, ETC.
Fig. 1 shows a cradle for glueing up the steps. Let A be a piece of
wood about 18 inches long by 6 inches wide by 2 inches thick, and B
should be a piece about 2 feet 6 inches long by 3 inches wide by 2
inches thick. Put a ¾-inch mortise through B and tenon A into it. Well
glue and wedge, and pin as shown. Two of these should be made. It will
be noticed that E is cut out for the projection of the front edge of
the tread past D, which is the face of the riser, and the mortise in B
is kept back to E. F is cut out to fit over the scotia. The holes in
the edges C and D are for pins to go in, to wedge against when glueing
up the steps. The process of glueing up the steps is as follows: first
cut off treads, risers, and scotia about 1 inch or 1½ inch longer than
their proper length. Now plane up the treads, and shoot the front edges
straight and square; then plough the under side for the scotia to go in
about ¼ inch deep; then plane up the scotia and gauge them to a width
and thickness so as to fit tight into the groove. These scotias should
next be glued into the grooves and allowed to dry while the risers are
being planed up. Plane up the face of the risers, and shoot the edge
to go against the tread straight and square. Now fix the two cradles
on the bench, by screwing them through B into the top of the bench. In
fixing these, try them with one of the treads so as to get them square;
keep them about 6 inches from each end.
Fig. 2 shows one of these cradles with a part of a step glued up. Lay
the step on the cradle and stick a pin in one of the holes in B, and
put in a wedge between the pin and the back edge of the step to keep
the step in its place. Now glue the tread for the edge of the riser,
also the back of the scotia; well rub the riser to get the glue rubbed
out, and put in the wedge to keep the riser down, as shown. Then put in
two screws and three blocks as shown at Fig. 7, Plate II. In putting on
the blocks take care to well rub the glue out.
Fig. 3 shows a part of the outer string housed out for the treads and
risers. The steel square is used to get the lines on the strings for
the treads and risers, as shown. Get a piece of stuff long enough,
marked F, and let it be about 2 inches square; put a good thick saw
cut in each end and slip the square in the cuts as shown. Hold the
hypothenuse of the pitch board against the fence F and set the blade to
the going, and the tongue of the square to the rise of the pitch board.
Now to mark the string. Gauge the hypothenuse line about 2½ inches from
the top edge of string, and make the distance between A A on this line
equal the hypothenuse of the pitch board. Slide the square along from
A to A and mark both treads and risers. To mark the housing on the
back side of the treads and risers, get two pieces of thin stuff and
cut wedge-shaped, allowing them the wedge wider than the thickness of
treads to mark the housing for the treads, and the wedge wider than the
thickness of the risers for the housing for the risers. Fig. 4 shows a
section of the steps with bracketed carriages showing. These carriages
are only used in this description of stairs; they average from 2 inches
to 3 inches thick; they are put on with the grain running in the same
direction as the strings, they are screwed to the under side of the
steps and to each other, as shown, and well blocked to treads and
risers. They are placed according to the width of the stairs, three
under each flight.
Fig. 5 shows a part of the wall string, moulded to match the skirting,
and housed out for treads and risers. In putting stairs of this sort
together, lay the wall string on the ground, as shown, taking care
to get it straight and solid. Then place one end of the steps in the
grooves of the wall string, after all the steps have been placed in
position, then lay the outer string on the ends of steps, and after
the steps have been got into the grooves. Well strut from the ceiling
or any convenient place on to the outer string, forcing the steps into
all the grooves. Then put in the wedges, glueing them before they are
driven in. After they have been screwed up and blocked the struts can
be removed.
The nosing and scotia are worked after the steps have been glued up;
this is the best method of working in either a machine or a hand shop.
Fit the nosing and scotia into the strings on the bench before putting
together, also get the rises to a width and number each step where it
is to go.
Fig. 6 shows how the strings are tenoned into the newel; the dotted
lines show the tenons and the haunching, the tenon being 3 inches deep
and the haunching ½ inch deep; this is shown at Fig. 7. The housing out
of the newels is described later on where there are winders.
The thickness of treads, &c., varies according to the class of work,
but the following may be taken as a good example.
Treads, 1¼ inch thick. Project over risers, 1¼ inch.
Risers, 1 inch thick.
Scotia, 1¼ inch by ⅝ inch.
Strings, 1½ inch.
[Illustration: PLATE 4.]