ledges and overhangs that could harbor
birds. They should also contain sanitary
seals against rodents and insects. Driveways
should be paved and free of vegetation,
trash, and water accumulation areas. Regu-
lar sweeping should be conducted to keep
dust from blowing into storage areas. Other
exterior design considerations may be found
in Chapter 14.
Interior Design
Walls and Framing
Exposed structural members may be satis-
factory in non-product areas, as long as they
can be kept clean and dust free. Reinforced
concrete construction is preferred for prod-
uct areas, and interior columns should be
kept to a minimum. Personnel doors should
be fitted using self-closing devices (hydraulic
or spring hinges) and screened. Gaps at door
bases should not exceed 0.6 cm, and 20-mesh
(minimum) screening should be incorpo-
rated.
Walls should be free of cracks and
crevices, and impervious to water and other
liquids to permit easy and effective cleaning.
Wall finishes should consist of food
approved materials, as dictated by the func-
tion of each area. Glazed tile for surface fin-
ishes on processing area walls should be
considered, with Fiberglass reinforced
plastic panels painted with epoxy or coated
with other materials meeting the company
and regulatory standards. Alternatives to
painting in food areas should be considered
because, although paint is inexpensive, it
tends to crack, flake, and chip with age, and
requires frequent maintenance replacement.
Insulation should be installed carefully in
bakery facilities because it constitutes a
potential dust and insect harborage. Even
though inert, it should be applied to the out-
side of the building.
Ceilings
The use of suspended ceilings is satisfac-
tory in nonfood areas if the space above the
ceiling can be inspected and kept free of
pests, dust, and other debris. Ceiling panels
must be sealed into the grid but be easily
removable. This feature is difficult to accom-
plish with most designs.
Suspended ceilings are not recommended
in food production or handling areas. They
can become a shelter for pests and may
become moldy if wet, thus providing a source
of contamination. In flour handling areas of
bakeries, dust may accumulate above the ceil-
ing very rapidly, leading to insect, microbial,
fire, and even explosion hazards.
Walsh and Walker (1990) recommend that
overhead structural elements, such as bar
joists and support members, be avoided
whenever possible. Precast concrete roof
panels provide a clean, unobstructed ceiling.
Precast panels can be fabricated with a
smooth interior surface, coated to resist dust
accumulation, and easily cleaned. Overhead
equipment supports; gas piping; water,
steam, and air lines; and electrical conduits
should be designed to avoid passing over
exposed food areas, cluttering the ceiling,
and dripping dust or moisture onto people,
equipment, and product. A mechanical
mezzanine to house utility equipment above
can result in an easily cleaned ceiling, free
from horizontal pipe runs and ductwork
(Figure 15–1).Floors
Floors in wet-washed areas must be
impervious to water, free of cracks and
crevices, and resistant to chemicals and
acids. Yeast food solutions are particularly
corrosive. Floor joints must be sealed, and
wall junctions must be covered and sealed.
Expansive concrete should be used wheneverLow-Moisture Food Manufacturing and Storage Sanitation 269