hardware clothor any other long-lastingmaterial that willwithstand rodent
gnawing. Any penetrations belowgrademust be protectedand sealed.If a
number of pipelinesenter at one spot thensurroundthemwitha galvanizedfine
meshscreenor hardware clothto preventrodent incursion.Cone guards can be
usedon vertical pipelinesas wellas flat guards.Whatever typeyourdesigner
decideson must keepthe rodents fromgaining access.
7.9.4 Interior walls
Interiorwalls are constructed fromnumerousmaterials, ranging fromtile,
cementblock,concrete, metal,reinforcedfiberglass paneling, bakedon enamel
insulatedmetalpanels, resinmaterials withbuilt-inantimicrobialsas well as dry
wallin selectedareas.Dry wallshouldnot be usedin any areawhere thereis
moistureor wash-down cleaning,or any kindof foodprocessing takingplace.
Whatever typeof material is used,thereare certain criteriathat must be met for
it to be considereda sanitary wallfor foodprocessingplants.According to
Katsuyama(1993),the walls should conformto the following standardsof
sanitary designand construction:
∑ The junctureof the roofwiththe wallshould be weather- and rodent-proof.
Wall plates should be sealed to prevent insect entry and avoid dust
accumulation.
∑ Double wallsof frame construction should have built-in rat stops. The
insulation material must be unattractiveto rodents for nesting.
∑ The insidesurfaces of the wallshouldbe water-resistant,smooth, washable,
and easilycleaned.Thereshouldbe no ledges to collect dust and debris.All
roughor irregular surfaces in concrete wallsshould be rubbed or ground
smoothto reducedustand dirt accumulation;wheregrainand flourdust
occur,suchaccumulationscan becomebreedingspots for insects.
∑ All wallopenings shouldhavetightly fitting doors, windows,or screens to
excluderodents,insects, and otherpests.
∑ Flat surfaces,suchas horizontal braces,should be slopedat about45Î to
preventtheiruse for storageof personaland miscellaneous items.
∑ Particular attention shouldbe givento areasthat are subjectto splash and
spray.They shouldbe surfacedto facilitate quick,easy,and frequentcleaning
or flushing.
∑ The floorjuncture of framedwalls is of primaryimportance to sanitation. Its
properconstruction and maintenance are essentialto adequate rodent control
and general housekeeping. Thejuncture of the interiorwall shouldbe
watertightand builton a covedbaserisingto a height of at least6 inches
(150mm)abovethe floorlevel. Cornersshouldbe rounded to facilitate
cleaning.
Companiesare continuallydeveloping wallmaterial that is cleanableand
sanitary. Mostmaterials now are whiteor verylightcolored.The material needs
to be resistantto the cleaning and sanitizingcompoundsusedin the facility.
Improvingbuildingdesign 137