damage. Anchor walls and partitions to adjoining construction to provide
lateral stability. Anchoring shall permit unrestricted deflection of
construction above.
3.1.2
Mortar Mixing
ASTM C 270. Hand mixing may be used only when specifically approved by the
Contracting Officer. Mortar boxes, pans, and mixer drums shall be kept
clean and free of debris and dried mortar. Do not retemper mortar. Do not
use mortar which has not been placed in final position within 1 1/2-hours
after the initial mixing.
3.1.3
Mortar Joints
Mortar joints shall be accurately spaced, uniform in thickness and average
thickness shall be 10 mm 5/16 inch. Fill joints completely and evenly.
Remove loose and excess mortar. Horizontal joints shall be level; vertical
joints shall be plumb. Paint surfaces upon which first course of glass
blocks is to be laid with heavy asphalt emulsion before spreading first
mortar bed. Emulsion shall be thoroughly dry prior to spreading mortar.
When asphalt is dry, place full mortar bed joint. Furrowed or raked joints
will not be allowed.
3.1.4
Care During Laying
Do not damage glass block while laying or otherwise. Lay block with
[stacked bond] [_____]. Form bed joints of a thick layer of mortar, smooth
on top, not furrowed. Form head joints by applying a full coat of mortar
on the entire end, or on the entire side, of the block to be laid and then
shoving the mortar-covered end or side of the block tightly against the
block laid previously. The practice of buttering at the corners of block
and then throwing mortar or scrapings into the empty joints will not be
permitted. Lay closure blocks with a bed joint and with head joints, and
place the block carefully without disturbing the block previously laid.
Dry or butt joints will not be permitted.
3.1.5
Reinforcing
Embed horizontal reinforcing in mortar joints on approximately [600 mm
center for 98 mm 24 inch centers for 3 7/8 inch thick glass block] [and] [
400 mm centers for 76 mm 16 inch centers for 3 1/8 inch and 3 inch thick
glass block], and in the first joint above and below all openings. Run
reinforcing continuously from end to end of panel, except at expansion
joints, and lap not less than 150 mm 6 inches where more than one length
is used.
3.1.6
Panel Anchors
Crimp in expansion joints, placed 600 mm 24 inches apart (in same joint as
panel reinforcing), and completely embed in the mortar joint. Build
members as appropriate. At the option of the Contractor, suitable anchors
may be fastened to masonry and concrete and to steel framing by means of
powder-actuated fasteners in lieu of being built-in or welded.
3.1.7
Expansion Allowance
Provide space indicated to permit expansion at heads and jambs, and fill
void with expansion strip.
SECTION 04270
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