Store windows only 5 or 6 feet wide between posts or piers usually have the glass set in a stationary sash, which is made in essentially the same way as smaller sash, and either 1 ¾ or 2 ¼ inches thick. If double-strength glass is used the sash is generally divided into large lights by wood muntins about ¾ inch or 1 inch wide between the glass.
When plate glass is used the lower light is generally the full width of the sash and from 6 to 7 feet high, with a wood muntin or transom bar across the top, or if the light above is also of plate glass, and it is desired to give the appearance of a one-light window, an iron muntin, or sash bar, of the section shown at C, Fig. 118, and covered with thin nickel-plated brass over wood, is placed between the lights. Such small bars are only suitable for lights not over 6 feet wide.
In the principal retail stores of large cities it has become the custom to make the entire front of the store one large window, with lights of plate glass from 6 to to feet wide and 7 or 8 feet high, with other lights about 3 or 4 feet high above them. la such store fronts framed sash are not used, but small posts or sash bars are set up between the lights, extending from the sill to the top of the window, and other similar bars are cut between them at the height of the lower light, thus making a framework to hold the glass.
As the desire of the ordinary merchant is to have as much plate glass as possible, the columns which support the wall above are usually set 4 or more inches inside of the wall line, and the plate glass not more than 1 ½ inches inside of the line, and sometimes flush with it, so that the window may be placed in front of the column and extend unbroken, except by the entrances, from corner to corner.
Fig. 112. - Sash Bars.
It is also the fashion to make the bars which separate the lights of glass of the least size which will give sufficient strength to hold the glass and prevent the window from being blown in. In the better class of stores the outside of the sash bars is usually covered with ornamental metal, and quite often iron bars are placed between the wood to give the necessary strength and to prevent warping.
Fig. 118 shows types of sash bars in most common use in large windows, although they may be varied in size and in the detail of the mouldings. Sections A, B, D, E and F are drawn to one-fourth of the usual size.
Sections A and B are quite common in Chicago. The strength of the bar is afforded by a cast iron T, of which only the front is exposed. The front is generally copper plated and oxidized, and often ornamented by relief work. The T is filled out to a square by pieces of thoroughly seasoned wood, screwed or bolted together as shown. Wooden stops are then screwed to the wood core to hold the glass, or iron stops may be used if preferred, but hard wood is probably better. The usual size of sash bars of this pattern appears to be 3 inches wide and 2 ½ inches deep, exclusive of the inside casing and stops, but they can be reduced to 2 ½ inches wide and made 3 inches deep. The section at B is for an angle in the window. When the angle is a right angle the cast web may be omitted and the facing screwed to a solid piece of wood.
Sections E and F are quite extensively used in all large cities, and as a rule will be found cheaper than the cast iron bars. In these bars the whole construction is of wood, which should be of the best quality of white pine or cypress, the glass being held by a half-round strip screwed to the bar. The half-round is covered on the outside with thin brass or copper, which may be nickel plated or oxidized, the metal extending over the edge about ¼ inch to hold it in place. Such bars have the appearance of being of solid metal. They are carried in stock in sizes of 2, 2 ½ and 3 inches, or can be made to order. They can also be adapted to any angle in the manner shown at F.
The wooden bar forming the support is, of course, made by the carpenter, and should be about 2x3¾ inches. It may be plain or moulded, as desired.
Sometimes a wrought iron bar about 3/8X3 inches is placed in the centre of the wood bar, corresponding to the web of the T, detail A, and the metal-covered bar is screwed into the edge of the iron bar, as shown by the dotted lines. This adds much to the expense and does not appear to be necessary if the wooden bars are made of the size above indicated.
The cross bars are generally made of the same section as the upright bars, although it is not necessary to do so.
The detail at D shows a wooden transom bar which has been used in connection with the upright bar E with very good effect.
Whatever may be the shape of the bars, the upright bars should always extend from sill to head in one length, and the horizontalarsb should be cut between them.
With bars of the shape shown at D, E and F, it is of course necessary to set the glass from the outside, and it is generally considered best that all glass should be set from the outside, although where fixed sash are used in store fronts the glass is often, for convenience, set from the inside.
Fig. 119 shows a section through the sill and "bulkhead" of a store window, where the bulkhead is of fireproof construction. If the rest of the store front is faced with iron, the front of the sill may also be treated in the same way, the facing being screwed to the wood,
Considerable difficulty is often experienced with store windows in preventing their becoming covered with frost in cold weather. For this reason small inlets for air are often provided in the sill and transom, as shown in Fig. 119 and at D, Fig. 118, to afford ventilation and to permit of the escape of moisture that may gather on the inside of the glass.