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1947-48 Theatre Catalog, 6th Edition, Page 184 (172)

1947-48 Theatre Catalog, 6th Edition
1947-48 Theatre Catalog
1947-48 Theatre Catalog, 6th Edition, Page 184
Page 184

1947-48 Theatre Catalog, 6th Edition, Page 184

RADIANT HEATING COILS can be laid on vermiculite insulating concrete, an application which, as readers of this volume (1945 edition, pages 375 through 378) can well appreciate. is coming into more and more wide A survey shows that there are now about 1,000 radiant-heat floor


facture of a lightweight, insulating concrete. (See Table 2.) The vermiculite concrete aggregate is mixed with Portland cement and water. In its use, caution should be exercised to secure concrete aggregate which has been produced according to the standards of the Vermiculite Research Institute. This material incorporates an integral admixture which lends conformity, maximum yield, strength, and certain water-proofing characteristics to the finished mix. Vermiculite insulating concrete is extensively used in providing warm dry floors and insulating roof decks. This is perhaps the only method that provides a monolithic insulating floor construction for theatres.

Vermiculite concrete has proved itself very versatile in insulating concrete roof construction. It provides an insulating

' fill over existing roof decks of concrete, wood, asbestos, steel, or corrugated iron. Or it can be used as a structural deck itself, furnishing insulation and structural strength in one application, through a variety of methods not found

TABLE 3 Sound absorption test.


with any other material. Structural roof decks of vermiculite concrete may be poured over paper-backed welded wire mesh, ribbed metal lath, or other supporting forms.

The most clearly evident advantages in the use of vermiculite for this purpose are in the reduction of dead load on supporting structural members and its extremely high fire-resistive characteristics. In one 33-story building, fioors, columns, and beams fire-proofed in this manner permitted savings in dead load and the use of structural steel of $235,000! This represented only the saving in cost of structural steel; many additional economies were effected in placing, handling, and forming of the material. In lesser amounts, the same economies can be achieved where new theatre construction is planned.


In theatre construction calling for a granular-fill insulation to prevent heat loss in loft and side-wall cavities, vermiculite affords the same fire-proof pro Coetticient of sound absorption recorded for

Zonolite acoustical plastic, 1/2 inch thick, after being painted with two and four coats of water paint. (From tiZonolite Acoustical Plastic? published by the Uni versal Zonolite Insulation Company.)


FREQUENCY COEFFIClENTS* COEFFICIENTS* (cycles per second) 2 coats 4 coats I28 .31 .30 256 .32 .37 512 .52 .59 1024 .81 .84 2048 .88 .74 4096 .84 .65 Noise Reduction CoeMcient .65 .65 M

*As determined by a Nationally known laboratory. Meets Federal Specifications SS-A-Ill, Acoustic Materials, Type II, Classes I

and FF.



installations being put in each month in residential and commercial struc.

While an occasional theatre adopts this system, there is no reason why the methods of heating should not become more widespread, With the added advantage to be obtained from the use of vermiculite concrete.

tection as has been previously described.

Many graphic illustrations of the firel'esistance of granular-fill vermiculite can be pointed out. An egg, placed in the center of a coffee-pot filled with vermiculite, can be left for an hour in a hot oven, removed, and found to be raw. A penny placed on a small pile of vermiculite in a mans hand can be melted by blow torch without injuring the holder.

And vermiculite, being all-mineral, is roteproof and vermin-proof.


One of the more recent developments incorpurating vermiculite has been the manufacture of an acoustical plastic, now available throughout the country.

This material has been employed successfully in many theatres. It has a high sound-absorbing efficiency because of the inherent sound-proofing characteristics of vermiculite itself. (See Table 3.)

Vermiculite is comprised of many tiny laminations, between each of which is entrapped dead air cells which offer high resistance to the passage of heat. Cumulatively, these granules provide one of the most effective barriers to heat dissipation.

\Vhen this acoustical plastic is troweled on over existing surfaces, it presents a seamless monolithic surface, ideally adapted to the rendering of decorative murals and designs. When painted, none of the natural soundabsorbing efficiency of the material is hampered. An attractive rough-textured finish is achieved through the use of vermiculite acoustical plastic.


For complete insulation of theatres, combined with sound treatment and fire protection, vermiculite unquestionably provides the owner, architect and contractor with one of the most versatile building materials at his disposal.

1947-48 Theatre Catalog, 6th Edition, Page 184