Page 163 - Masonry and Concrete

Masonry Construction Techniques
162 CHAPTER FIVE

prevent gouging. Jointers for vertical tooling are small and S-shaped.
Although the material most commonly used for these tools is steel,
plastic jointers are used to avoid darkening or staining white or light-
colored mortars. After the joints have been tooled, mortar burrs or
ridges should be trimmed off flush with the face of the unit with a
trowel edge, or by rubbing with a burlap bag, a brush, or a piece of
carpet.
It is important that the moisture content of the mortar be consistent
at the time of tooling, or color variations may create a blotchy appear-
ance in the wall. Drier mortar tools darker than mortar that is wetter
when tooled. Along with time and weather conditions, brick moisture
content at the time of laying affects mortar curing time. An inconsis-
tent unit moisture content therefore affects the color of the finished
joint. If an unprotected pallet of brick, for instance, becomes partially
wet during an overnight rain, the wet units will cause patches of
lighter-colored joints because their higher moisture content keeps the
mortar moist for a longer period of time than adjacent areas.
Even with high-quality workmanship, some routine patching or
repair of damaged or defective mortar joints is to be expected. In addi-
tion, any holes left by line pins should be filled with fresh mortar
before the joints are tooled. The troweling of mortar into joints after
the units are laid is known as pointing. It is preferable that pointing
and patching be done while the mortar is still fresh and plastic, and
before final tooling of the joints is performed. If however, the repairs
must be made after the mortar has hardened, the joint should be raked
1
or chiseled out to a depth of about 2 in. thoroughly wetted, and
pointed with fresh mortar.

5.4.2 Flashing and Weep Holes

Flashing must be installed in continuous runs with all seams and joints
lapped 4 to 6 in. and sealed with a nonhardening mastic or caulking
material. Unsealed lap joints will allow water to flow around the end of
the flashing and penetrate the wall. At lateral terminations where the
flashing abuts other construction elements, and at terminations on each
side of door jambs, flashing must be turned up to form an end dam.
Flexible flashing can be simply folded into place (Figure 5-24).
Flashing should never be stopped short of the face of the wall, or
water can flow around the front edge and back into the wall. Flexible

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