CITY MILK PLANTS: CONSTRUCTION AND ARRANGEMENT. 11 
terial can be finished with a smooth surface which is sanitary and 
can be easily washed with the hose. Walls should be coated with a 
paint as nearly waterproof and steamproof as possible. When 
wooden walls or partitions are used, the concrete of the floor should 
extend about 2 feet up the wall, as that part of the wall is exposed 
to water a large part of the time. : 
For inside walls of rooms where milk is handled, enamel brick, 
tile, enamel cement, or cement plaster is satisfactory. Tile or enamel 
brick is preferable but rather expensive. The different materials 
used in 20 plants which had special material for these rooms were as 
follows: Enamel brick, 12 plants; tile, 4 plants; cement plaster, 1 
plant; enamel cement, 3 plants. 
All the foregoing materials have a smooth surface and are easily 
kept clean. They give the room a sanitary appearance and are good 
reflectors of light. Enamel brick is less expensive than tile and is 
much used for the walls of milk-handling rooms. 
Ceilings are usually constructed of materials similar to those used 
on the inside walls. The following were found in various plants: 
Wood, concrete, cement plaster, plaster on lath, and galvanized 
metal. As in the case of the inside walls, the ceiling should be 
smooth, durable, easily cleaned, and as nearly waterproof and steam- 
proof as possible. 
FLOORS. 
‘Several large plants had wooden floors, but wood is a very poor 
material for floors where milk is handled. Wood is not durable and 
the milk soaks into it, causing bad odors and insanitary conditions. 
If a wooden floor is very tight it may be satisfactory for a short time 
if it is cleaned often, but its period of usefulness is short. Some 
form of concrete with a waterproof finish is the most desirable ma- 
terial. Frequently a hardener of steel filings mixed with the cement 
~ is used to form the finish, which makes the floor wear better. Some- 
times, where an old building is used for a milk plant, a concrete floor 
may be laid over wood, if the underpinning is strong enough. If 
properly laid, a concrete floor is smooth and can be easily cleaned 
with hot water from a hose. Milk does not soak into concrete floors 
as it does into those of brick or wood. Concrete floors should have 
a good foundation with at least 34 inches of concrete below the top 
surface. Asphalt is sometimes used, but it is not very satisfactory 
because heat tends to soften it. 
A tile floor in the bottle-filling room is desirable. Although more 
expensive when properly laid, it makes a good appearance, is durable, 
easily cleaned, and very sanitary. 
Iron plates embedded in the cement protect the floor in rooms 
where cans and trucks are constantly being handled. An unpro- 
tected concrete floor wears out quickly if cans are continually rolled 
over it. 
