10.1 Introduction
Walls can be considered as the second most abused surface (after floors) in a
food processing plant. The Food and Drug Regulations, specifically 21 CFR,
Part 110 (the current good manufacturing practice, CGMPs), require that the
floors, walls and ceilings in a food plant `be of such construction as to be
adequately cleanable and kept clean and in good repair.' Walls serve a number
of purposes in food facilities, depending on whether they are interior or exterior
structures. The type of processing that takes place also has a bearing on the type
of wall necessary. That is, does it have to withstand hot water wash-down, does
the wall enclose a refrigerated or heated space, is it cleanable, and how does it
protect the processing space from seasonal changes and extremes in outside
temperatures? There are numerous materials that can be used for wall
construction, ranging from pre-engineered metal building walls to highly
sophisticated gel-coated materials that contain anti-microbial characteristics.
The choice depends on climate, plant location, local building codes, operating
season, cost and environmental factors. These are a few of the questions that
require answers when designing and constructing a sanitary food processing
facility. This chapter will deal with external and internal walls, and how to
integrate them into the entire facility.
10.2 Exteriorwalls
Concrete (precast or tilt up) exterior walls are usually load bearing and provide a
support for the roof. Exterior walls and the foundation they rest on must provide
10 Improvingthe designof walls
D. J. Graham, Graham Sanitary Design Consulting Limited, USA