wash, nor will paint cover them. Allow droppings to
dry and harden. You can then chip off most of the
mortar with a small piece of broken concrete block
(figure 8-29, view 1) or with a trowel (view 2). A
final brushing of the spot removes practically all the
mortar (view 3).
The purpose of a retaining wall is to hold back a
mass of soil or other material. As a result, concrete
masonry retaining walls must have the structural
strength to resist imposed vertical and lateral loads.
The footing of a retaining wall should be large enough
to support the wall and the load of the material that the
wall is to retain. The reinforcing must be properly
located as specified in the plans. Provisions to
prevent the accumulation of water behind retaining
walls should be made. This includes the installation
of drain tiles or weep holes, or both.
PAINTING CONCRETE MASONRY
Several finishes are possible with concrete
masonry construction. The finish to use in any
specific situation should be governed by the type of
structure in which the walls will be used and the
climatic conditions to which they will be exposed.
Paints now commonly used on concrete masonry
walls include portland cement paint, latex paint,
oil-based paint, and rubber-based paint. For proper
application and preparation of the different types of
paint, refer to the plans, specifications, or manu-
Figure 8-29.-Cleaning mortar droppings from a concrete block wall.