tight. Vertical joints of brick and the vertical face shells of concrete
masonry units, except where indicated at control, expansion, and isolation
joints, shall be completely filled with mortar. Mortar will be permitted
to protrude up to 13 mm 1/2 inch into the space or cells to be grouted.
Means shall be provided to prevent mortar from dropping into the space
below. In double wythe construction, the inner wythe may be brought up not
more than 400 mm 16 inches ahead of the outer wythe. Collar joints shall
be filled with mortar or grout during the laying of the facing wythe, and
filling shall not lag the laying of the facing wythe by more than 200 mm 8
inches.
3.2.1
Forms and Shores
Provide bracing and scaffolding as required. Design bracing to resist wind
pressure as required by local codes. Forms and shores shall be
sufficiently rigid to prevent deflections which may result in cracking or
other damage to supported masonry and sufficiently tight to prevent leakage
of mortar and grout. Supporting forms and shores shall not be removed in
less than 10 days.
3.2.2
Reinforced Concrete Masonry Units Walls
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NOTE: For single-wythe, concrete masonry unit
exterior walls, specify water-repellant admixture
for both the masonry units and the mortar. This is
a regional requirement which shall be used, when
applicable, for SOUTHNAVFACENGCOM projects; when
appropriate, the requirements may be used for
projects in other areas. Use only with ASTM C 744
masonry units.
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Where vertical reinforcement occurs, fill cores solid with grout. Lay
units in such a manner as to preserve the unobstructed vertical continuity
of cores to be filled. Embed the adjacent webs in mortar to prevent
leakage of grout. Remove mortar fins protruding from joints before placing
grout. Minimum clear dimensions of vertical cores shall be 50 by 75 mm 2
by 3 inches. Position reinforcing accurately as indicated before placing
grout. As masonry work progresses, secure vertical reinforcing in place at
vertical intervals not to exceed 160 bar diameters. Use puddling rod or
vibrator to consolidate the grout. Minimum clear distance between masonry
and vertical reinforcement shall be not less than 13 mm 1/2 inch. Unless
indicated or specified otherwise, form splices by lapping bars not less
than 40 bar diameters and wire tying them together.
3.2.3
Concrete Masonry Units
Units in piers, pilasters, columns, starting courses on footings, solid
foundation walls, lintels, and beams, and where cells are to be filled with
grout shall be full bedded in mortar under both face shells and webs.
Other units shall be full bedded under both face shells. Head joints shall
be filled solidly with mortar for a distance in from the face of the unit
not less than the thickness of the face shell. Foundation walls below
grade shall be grouted solid. Jamb units shall be of the shapes and sizes
to conform with wall units. Solid units may be incorporated in the masonry
work where necessary to fill out at corners, gable slopes, and elsewhere as
approved. Double walls shall be stiffened at wall-mounted plumbing
fixtures by use of strap anchors, two above each fixture and two below each
SECTION 04200
Page 40
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