Cork insulation; a complete illustrated textbook on cork insulation ...

224 CORK INSULATION
ating less heat than non-metallic surfaces, although since not
over 10 per cent of all heat normally entering an insulated
cold storage room through its surfaces is traceable to radiation
and convection combined, the insulating effect of the aluminum
paint is of negligible importance, and the finish should
be valued alone for its utility as a coating and preserving
material.
On floors, it is customary and very satisfactory to use concrete
over <strong>insulation</strong>, such concrete troweled hard and smooth
and sloped to drain. In ice storage houses the concrete should
be of increased thickness, or contain reinforcing mesh, or
both, on account of the weight to be supported. In fur stor-
ages, the desire is often for a wood floor of maple, which is
satisfactory in dry rooms if properly laid. In milk rooms,
and generally wherever metal containers must be moved over
floors, metal grids should be imbedded flush in the concrete
in fact the use of such metal grids is increasing rapidly in
cold storage rooms of every kind.
Lumber in cold storage rooms, as exposed ceiling con-
struction where <strong>insulation</strong> is applied above, or as bunker con-
struction, or as spacing strips on the floors and walls of ice
storage houses, or as bumper plates around the walls to
protect the finish from boxes and barrels, should not be creo-
soted before installation, because of the danger from odors,
but should be properly painted immediately afterwards and
before the cold storage room is put in service.
100.—Asphalt Cement and Asphalt Primer.—Authentic
evidence exists that asphalt was known for its useful and
valuable properties almost as far back as our knowledge of
civilization extends. The earliest recorded use of asphalt
was by the Sumarians, inhabitants of the Euphrates Valley
before the ascendency of the Babylonians. Unearthed relics
demonstrate that as early as 3000 B. C, asphalt was used by
these people as a cement for attaching ornaments to sculp-
tures, carvings and pottery. An asphalt mastic cast excavated
at Lagash, near the mouth of the Euphrates, dates back
to 2850 B. C, and as early as 2500 B. C. the Egyptians utilized
melted asphalt as a preservative coating for the cloth wrappings
of their mummies.
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