The stair posts, if made of hard wood, should be built up out of thin pieces. Turned posts of hard wood are not usually desirable, as if turned from a solid stick they are very apt to check, and if glued up to open at the glue joints. A newel, such as shown in Fig. 299, should be built up in the same way as the Corinthian column shown in Fig. 285. Angle posts should be extended below the outside string and should have an ornamental drop at the bottom.
In principal staircases the architect should provide for a half post where the rail terminates against a wall, as otherwise the stair-builder will fasten the rail to a wooden or iron plate screwed to the wall, which does not make as neat a finish as the half post.
Hand-Railing. - The section of the hand-rail is more a matter of taste than of construction and may be designed to conform to the interior finish. As a rule, however, the section of the rail should contain at least 9 square inches, 3 ½x3½ inches being a very good size. Several good sections are shown in Fig, 310, the scale being one-fourth full size. The section at D is preferred by many for public buildings, but for residences one of the other sections seems more pleasing and appropriate.
A safe rule for the height of the rail is to make it about 2 feet 6 inches above the tread, on a line with the face of the riser. For grand staircases the height is sometimes reduced to 2 feet 4 inches, but for steep stairs it should never be less than 2 feet 6 inches. The rail should also be raised over winders, especially those of a steep pitch.
On the landings the height of rail should be equal to the height of the stair rail measured at the centre of the tread, the usual height in residences being 2 feet 8 inches to a feet 10 inches.
In ordinary stairs the rail is generally straight, joining the posts at an oblique angle, as in Fig. 300. At the angle posts the rails, if made straight, will strike the post at different heights on the opposite sides of the post, and to overcome this the rail is often ramped, as shown in Fig. 299, the height of the ramp being made such that the rails on each side of the post will come at the same height.
The lower end of the rail is also often finished with an easing (in English books termed knee or kneeling), as shown in the same figure. Ramps and easings add much to the appearance of a stair, but they also add to the cost, and the stair-builder cannot be expected to put them in unless they are mentioned in the specifications or shown on the stair drawings.
Wall Rails. - Stairs which may be used by large numbers of people should have a rail on the wall side of the stair when 4 feet wide, and also all stairs built between partitions should have at least one wall rail. These rails are generally made with a round section of about 2 ¼ inches in diameter, and should be fixed to the wall on iron or bronze brackets made for the purpose. The ends of the rails are sometimes left straight, but it is better to return them against the wall.
Stairways from theatres and large halls, when over 12 feet wide, should have a rail in the centre, strongly supported,
All end joints in rails and connections between rails and posts should be made by means of joint bolts or hand-rail screws, of which three patterns are shown in Fig. 311.
Balusters are intended to support the hand-rail and to prevent any one from falling over the ends of the steps ; they may also be made an ornamental feature. They should be made of some kind of hard wood and may be of almost any size, although 1½ to 1 ¾-inch balusters are most largely used. They are generally square at the ends and turned or twisted between. Twisted balusters make a very handsome railing for residences, and were much used in Colonial mansions. They can now be turned by machinery at a very moderate cost. Generally two or three patterns are used, as shown in Fig. 312. In open string stairs the balusters should be doweled into the treads at the bottom and nailed or screwed to the under side of the rail. If the top of the baluster is round it should be doweled into the rail.
Usually two balusters are placed on each step, one flush with the face of the riser and the other half way between the risers. When the run exceeds 10 inches three balusters to the tread give a much nicer appearance, and in residences three 1 ½-inch balusters look much better than two larger ones.
There are two methods of arranging the turned portion of the balusters in open string stairs. One is to keep the square base the same height on each step, varying the height of the turning as shown at A, Fig. 299, and also in Fig. 312, and the other is to make the turned part of the baluster of the same length in each, varying the height of the square part to conform to the rake of the stairs, as shown at B, With a close string every baluster is alike, although with this style of stair open panel work or heavy balusters and arches are often used instead of the ordinary balusters.
Geometrical stairs have no newel or angle posts. The flights are arranged around a well hole in the centre, as in the plan Fig. 293, and each step is supported by having one end housed into the wall string and the other end resting upon the outer string, but partly drawing support from the step below it. The face string is generally strengthened by a flat iron bar screwed to its under side. The hand-rail is uninterrupted in its course from top to bottom.
Fig. 313 shows a sectional elevation of a geometrical stair with winders.