The final stage of most construction projects is the
application of protective coatings, or painting. As
with all projects, you should follow the plans and
specifications for surface preparation and application
of the finish coat. The specifications give all the infor-
mation you need to complete the tasks. But, to have a
better understanding of structural coatings, you need
to know their purposes, methods of surface prepara-
tion, and application techniques.
PURPOSES OF STRUCTURAL
LEARNING OBJECTIVE: Upon completing
this section, you should be able to state the
purposes of the different types of structural
coatings and how each is employed.
The protection of surfaces is the most important
consideration in determining the maintenance cost
of structures. Structural coatings serve as protective
shields between the base construction materials and
elements that attack and deteriorate them. Regularly
programmed structural coatings offer long-range pro-
tection, extending the useful life of a structure.
The primary purpose of a structural coating is
protection. This is provided initially with new con-
struction and maintained by a sound and progressive
preventive maintenance program. Programmed paint-
ing enforces inspection and scheduling. A viable
preventive maintenance program will help ensure that
minor problems are detected at an early stagebefore
they become major failures later. An added advantage
derived from preventive maintenance is the detection
of faulty structural conditions or problems caused by
leakage or moisture.
Resistance to moisture from rain, snow, ice, and
condensation constitutes perhaps the greatest single
protective characteristic of paint, the most common
type of structural coating. Moisture causes metal to
corrode and wood to swell, warp, or rot. Interior
wall finishes of buildings can be ruined by moisture
entering through neglected exterior surfaces. Porous
masonry is attacked and destroyed by moisture. There-
fore, paint films must be as impervious to moisture as
possible to provide a protective, water-proof film over
the surface to which they are applied. Paint also acts
as a protective film against acids, alkalies, material
organisms, and other damaging elements.
Painting is an essential part of general main-
tenance programs for hospitals, kitchens, mess halls,
offices, warehouses, and living quarters. Paint
coatings provide smooth, nonabsorptive surfaces that
are easily washed and kept free of dirt and foodstuffs.
Adhering foodstuffs harbor germs and cause disease.
Coating rough or porous areas seals out dust and
grease that would otherwise be difficult to remove.
Odorless paints are used in these areas because
conventional paint solvent odors are obnoxious to
personnel. In food preparation areas, the odors maybe
picked up by nearby food.
Certain types of structural coatings delay the
spread of fire and assist in confining a fire to its area
of origin. Fire-retardant coatings should not be
considered substitutes for conventional paints. The
use of fire-retardant coatings is restricted to areas of
highly combustible surfaces, and must be justified and
governed by the specific agencys criteria. Fire-
retardant coatings are not used in buildings containing
automatic sprinkler systems.
Camouflage paints have special properties,
making them different from conventional paints.
Their uses are limited to special applications. Do not
use camouflage paints as substitutes for conventional
paints. Use this paint only on exterior surfaces to
render buildings and structures inconspicuous by
blending them in with the surrounding environment.