TM 5-809-3/NAVFAC DM-2.9/AFM 88-3, Chap. 3
(3) Reinforcing steel must be properly posi-
(10) Ceramic glazed and prefaced masonry
units should be set level and true so that the glazed
tioned and held in place for grouting and mechani-
cal vibration. Lap lengths must be as required by
and prefaced facing will present true planes and
the contract drawings. Unapproved interruptions of
surfaces free of offsets or other distortions.
(11) Masonry unit protection. Tops of
reinforcing steel for openings must not be allowed.
The structural engineer should be contacted when
masonry that are exposed to rain or snow, while
conflicts arise.
being stored and in partially constructed walls,
(4) Air spaces in anchored veneer walls must
must be covered with nonstaining waterproof
be kept free of excessive mortar droppings. This
covering or membrane when work is not in
will allow water that passes through the outer
progress. Covering must extend a minimum of 2
masonry wythe to proceed downward in the air
feet down on each side and be held securely in
space to reach the flashing and exit through the
place. The covering should allow air movement so
weepholes.
that the masonry can reach ambient moisture
(5) Brick expansion joints, both vertical and
(12) Other items critical to the specific
horizontal, must be kept free of all material,
project should also be included, such as, prism
including mortar, and then sealed with backer rods
and sealant. Compressible material that is installed
testing of high strength masonry, etc.
d. Site visits. The final step in the design/con-
in the expansion joint for the purpose of keeping
mortar out of the joint, etc., should not be used.
struction process to achieve quality masonry con-
(6) Masonry bonding at the corners is re-
struction is site visits by the designer. The purposes
quired. This detail is needed to provide adequate
of these visits by the designer are:
lateral support to corners of walls during and after
(1) To see that the design intent is being
construction.
reflected in the construction.
(7) Joint reinforcement must be the type
(2) To facilitate discussion between the con-
specified, usually the ladder type, and must be
struction field office personnel and the designer on
properly placed. One longitudinal wire will be
special features of the design and critical construc-
installed in each mortar bed. This normally requires
tion items.
two longitudinal wires per concrete masonry unit
(3) To provide feedback on construction
(CMU) wythe and one longitudinal wire per brick
problem areas and to develop design
wythe. Truss type joint reinforcement should not be
improvements.
used. Factory fabricated intersections and corners
(4) To open the lines of communication be-
are required. Longitudinal wires should be properly
tween the designer and field personnel so that
located within mortar beds to provide needed
problems and concerns will be more freely dis-
corrosion protection.
cussed. Although it is recognized that the degree of
(8) insulation panels used in cavity wall con-
engineering support during construction is under
struction must be in close contact at all pane] edges
continual time and cost constraints, the need and
and must be tightly adhered to the backup wythe to
value of site visits by the designer has been clearly
achieve the assumed U-value.
established in published guidance. Every effort to
(9) Flashing must be installed so that cells to
implement a program of site visits during critical
be grouted are not blocked. Thus, flashing that is
phases of masonry construction should be made.
identified as "thru-wall" should not extend further
The designer should not make field visits only in
into the masonry backup wythe than the first
response to field problems. Note that the
mortar bed. Joints in flashing must be lapped and
"Instructions to the Field" given above provide an
sealed. Properly sealed joints are especially critical
excellent short checklist both for the field quality
in wall systems with steel stud backup. Partial panel
assurance staff and for the designer during routine
length flashing for lintels, etc., should be turned up
field visits to masonry construction.
to form dams at the ends.
2-3
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