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1947-48 Theatre Catalog, 6th Edition, Page 152 (140)

1947-48 Theatre Catalog, 6th Edition
1947-48 Theatre Catalog
1947-48 Theatre Catalog, 6th Edition, Page 152
Page 152

1947-48 Theatre Catalog, 6th Edition, Page 152



FIGURE IGeWhen the cinder till is properly leveled and compacted, the aisles should be located and the carpet strips and grounds installed to proper floor slope. If grounds are used, these will provide screeds for both the floor and the aisle, also provide a protection tor the edge of the carpet depression until such a time as the concrete is cured. Screeds are only temporary devices to save time and labor.

Orchestra Floor

As stated earlier, in order to provide for drilling clean holes for the expansion shields used to secure the chair standards, the top 2 inches of the concrete floors in the seating area should be composed of a mixture of one part of cement to one part of sand, and two parts of fine grit. This topping should be poured integrally with the rough slab which should be regular 2,500-p0und concrete with temperature reinforcement both ways. If this slab has a structural function then, of course, it Will be so designed and the necessary thickness and reinforcement computed. If the slab rests on the earth and is over areas that have been recently filled, then the slab should be properly reinforced to be self-supporting over such areas. A well compacted, 6-inch layer of Cinders or gravel should be installed immediately under the slab for drainage unless the nature of the soil is sandy and will supply the necessary drainage.

When the cinder fill is properly leveled and compacted, the aisles should be located, and the carpet strips and grounds installed to proper floor slope. If grounds as shown in Figure 13 are used, these will provide screeds for both the floor and the aisle, also provide a protection for the edge of the carpet depression until such a time as the concrete is cured. When the aisle screeds are located and installed, screeds should then be installed between the aisles to the exact curve of the seat rows, and at the elevations given for the floor. These screeds will only be temporary and will be removed before the adjoining portion of the floor is poured.

A hardener should be mixed in the floor topping which can also be colored if desired. The hardener, however, is mandatory to prevent dusting of the floor.

As soon as the concrete is sufliciently set, it should be covered with a layer of heavy kraft paper or a layer of sand, and kept damp for at least seven days

to produce the proper curing. The covering should remain on the floor until the plastering and other heavy work is finished in order to prevent chipping and discoloration.

Wall Piers

If the interior design of the auditorium contemplates a side wall treatment which is not to be interrupted by columns or pilasters, then the inside of the enclosing theatre wall should be on a line with the inside of the masonry piers or the fireprooflng of the steel columns. This will save the cost of the furring necessary if the piers or columns project beyond the face of the inside wall.


A wainscot of hard wearing material should be installed all around the auditorium walls, but since such material will reflect sound, it should be kept down to average shoulder height or approximately 5 feet from the floor. Wainscoting should be installed on these walls, even if no side aisles are used.

The wainscot can be marble, terrazzo, linoleum, or wood, but the most practical and the cheapest is a wainscot of well-troweled, smooth cement plaster which can be painted.

Since the finish wall above the wainscot will, in most cases be treated acoustically, and will therefore be 2 inches away from the rough masonry, it will be necessary to either furr out to bring the finish wainscot in line with the finish above, or a compensating moulding can be designed to overcome this distance. (See Figure 14.)


The schedule of construction should be such that the floor can be installed and cured before the scaffolding for the ceiling is erected. This scaffold will also be used for the painters and for hanging the auditorium draperies. Therefore, it will not be ready for dismantling until a few days before the theatre is ready to open. It is, of course, possible to

use a hanging scaffold in which case there will be no intereference with the pouring of the floor or the installation of the seating.

If such a scaffold is used, it should,

be suspended by steel cables from the roof structure and the added load imposed on the roof framing should be recognized in the structural design. Flanged sheet metal thimbles about 2 inches in diameter and 6 inches in length should be placed around the cables to be plastered in later with the bottom flange flush with the finished ceiling. To each thimble should be attached by means of a flexible chain or wire, a flat metal disk which will hang below the ceiling and can be painted to match the surrounding ceiling decoration. After the scaffolding is removed and the cables pulled up in the attic space through the thimbles, the disks can be pulled flush with the ceiling covering the holes and secured by means of the wire. The wire cables should remain attached to the roof structure and neatly coiled and greased for use when redecoration is required.

Ceiling Construction

The ceiling of the auditorium will, in all probability, be plaster on metal lath attached to furring which in turn is suspended from the roof structure. This ceiling, unless it is properly constructed, can be a source of danger to the patrons seated below and consequently a great responsibility of the theatre management.

The main members of the furring should be 1%. inches by 11/2 inches by 3/16-inch steel angles or 2-inch rolled steel channels, bent to the contour of the ceiling, hung by means of 1-inch by 3/ 16-inch flat iron straphangers, 4 feet on centers. These hangers should be securely attached to the structural roof members by means of special clamps and stove bolts, and to the runners by means of bolts through holes punched in the hanger and the angle. (See Figure 15.) Special care should be exercised to be sure that all these iron straphangers are under tension and carrying their portion of the load after the plastering is completed. Across the main furring angles or channels, iii-inch cold rolled channels, 12 inches on center are attached by means of approved wire clips. The metal lath is then attached to the channels using wire ties. This lath should weigh 3.4 pounds to the foot and should be treated for rust prevention.

All hangers and furring members should also be dipped in a rust preventive paint before being stalled or thoroughly painted after installation.

The plaster will be applied in three coats, namely, the scratch coat, brown coat, and finish or white coat. The scratch coat is of the utmost importance as it is the one which anchors the plaster ceiling to the metal lath. Sufficient pressure must be applied by the mechanic to force the scratch coat between the voids in the lath so it will mushroom out and completely enclose the lath on the top side as well as the bottom. The brown coat is next applied after the scratch coat dries out sufficiently and in no place should it be necessary to apply more than a thickness

1947-48 Theatre Catalog, 6th Edition, Page 152