There are two general types of stairways, the closed stair where the steps are built in between walls, and the open stair which may have a balustrade on one side and a wall on the other or balustrades on both sides. See Plate 58.

Following are a few general rules and reminders which should be observed in laying out a stair so as to obtain the most of comfort and safety in their use, and ease in their erection.

That part of the stair on which we step is called the tread and the vertical part of the step is called the riser. The total distance from floor to floor is called the rise and is equal to the sum of the heights of all the risers. The horizontal distance from the face of the bottom riser to the face of the top riser is called the run and is equal to the sum of all the treads. These are all noted on Plate 59.

So that one may take steps of normal length in walking up a stairway, the size of riser and tread must be considered carefully. The height of one riser plus the width of one tread should not be less than 17 inches and not more than 18 inches. Another good rule is to make two risers plus one tread equal 24 inches. A good average for residence work is to make the riser 7 inches and the tread 10 inches. Treads should never be less than 9 inches from face to face of risers of wood stairs or 10 inches for stone steps. The overhanging part of the tread is called the nosing and is not included when width of tread is figured nor is it shown on the scale drawings. See Plates 58 and 59. All risers must be the same height and all treads must be the same width on a stairway. Unequal treads or risers will form a stumbling place on the stair.

The steps of a curving stair are called winders and when they occur in the same stair with straight steps, the treads of the winders should be the same width on the walking line as those of the straight steps.

All stairways should be well lighted, both naturally and artificially.

A front stair should not be narrower than 3' - 0". The top of a handrail should be about 2' - 6" above the tread measuring vertically in the plane of the riser. This height may be increased to 2' - 8" or more where the rail runs level as on landings.

PLATE 58. TYPES OF STAIRWAYS

PLATE 59. STAIRWAY DETAILS

PLATE 60

[In A Drawing Of This Kind, Which Is Of Necessity Rather, Large, The Plan Is Often Drawn Directly On Top Of The Elevation A5 Here Shown. In So Doing Care Must Be Used That The Drawing May Not Become Confusing. Notice That Only One Baluster Or Spindle Is Drawn In Elevation While All Of Them Are Located On The: Plan. This Drawing Together. With A Scale Detail Of The Entire Stairway Describes Fully This Feature Of The Building.]

Handrails are either continuous with a curved portion or wreath where they change direction or else they are straight and have newel posts where they change direction as shown in Plate 59, Types of Handrail Turns. The last mentioned rail is usually the cheaper one to build. Starting newels should extend down through the floor and be bolted to the floor joist or else fastened to a timber which has been so bolted. Landing newels should carry down similarly through the landing so as to afford a secure fastening. The center line of the handrail should be on the center line of the newels and may be assumed to come directly over the face of the plaster wall or the wood panels below. See Plate 60. Where possible, let risers intersect newels on the center line of the newel. See Plate 58.

Special attention should be given to the head room on a stairway and this should never be less than 6' - 6" as shown by the stairway section on Plate 59, and should be 7' - 0" to 8' - 0 " if space will permit.

The construction to carry the stair must be kept in mind and sufficient space allowed for strings and carriages.'

It is always well and often necessary to draw a section through the stairway similar to that on Plate 59. This section should show the newels, balusters, rails, etc. Draw it in such a way as best to show the stairway. The one given on the plate is merely diagrammatic.

On the scale drawings should be shown in plan and elevation the location of the risers, the handrails and newels and a few general dimensions such as the rise, the run, the width to center line of handrail and the height of the handrail. Sometimes the risers are numbered beginning with the bottom riser. This is for convenience in reading the drawing. See Plates 22 and 37.

Sometimes only the mouldings of a stairway are detailed full size, but for good work, full-size details are made of the newels, rails, balusters and all mouldings, and sometimes of the entire start of the stair, such as that given on Plate 60.

The diagonal use of the scale as described by Fig. 30 on Plate 4 affords a handy way of laying off any number of steps quickly and accurately.

## Plate 61. Table Of Dlmensions

 WIDTH of OPENING HEIGHT OF OPENING DEPTH OF FIREPLACE DREAST WIDTH OF BACK. THROAT FLUE 'E "F" "G" 3'-0" 2'-4" 1'-4" 8" 1'-6" 4" 8'-12" 13" 10" 13" 3'-6" 2'-4" 1'-4" 8" 1'-6" 4" 12'-12" 13" 10" 13" 4'-0" 2'-6" 1'-4" 8" 1'-8" 4" 12'-12" 13" 10" 15" 4'-6" 2'-8" 1'-6" 8" 2'-0" 4" 12'-12" 14" 10" 16" 5'-0" 3'-0" 1'-8" 12" 2'-0" 4" 12'-18" 15" 12" 2l"