USACE / NAVFAC / AFCESA / NASA UFGS-04 23 00 (April 2006)
--------------------------
Preparing Activity: USACE Replacing without change
UFGS-04270 (August 2002)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 04 23 00
GLASS MASONRY UNITS
04/06
NOTE: This guide specification covers the requirements for glass block unit
masonry work.
Edit this guide specification for project specific requirements by adding, deleting,
or revising text. For bracketed items, choose applicable items(s) or insert
appropriate information.
Remove information and requirements not required in respective project, whether
or not brackets are present.
Comments and suggestions on this guide specification are welcome and should
be directed to the technical proponent of the specification. A listing of technical
proponents, including their organization designation and telephone number, is
on the Internet.
Recommended changes to a UFGS should be submitted as a Criteria Change Request
(CCR).
PART 1 GENERAL
NOTE: The following information will be shown on the project drawings:
1. Head, jamb, sill, and intermediate support construction details.
2. Clearances required for deflection and expansion.
Refer to manufacturers data for glass block unit panel size restrictions, limitations,
and details. CAUTION: 1) Single wythe construction is not recommended for
areas subject to severe wind-driven rain exposure; 2) avoid removable panel
construction; and 3) avoid large expanses of exterior walls subject to high
wind pressures, wide thermal variations, and differential movements
1.1 REFERENCES
NOTE: This paragraph is used to list the publications cited in the text of
the guide specification. The publications are referred to in the text by basic
designation only and listed in this paragraph by organization, designation,
date, and title.
Use the Reference Wizard's Check Reference feature when you add a RID outside
of the Section's Reference Article to automatically place the reference in the
Reference Article. Also use the Reference Wizard's Check Reference feature
to update the issue dates.
References not used in the text will automatically be deleted from this section
of the project specification when you choose to reconcile references in the
publish print process.
The publications listed below form a part of this specification to the extent referenced. The publications are
referred to within the text by the basic designation only.
[ASTM INTERNATIONAL (ASTM)ASTM A 153/A 153M(2005) Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel HardwareASTM A 82/A 82M(2007) Standard Specification for Steel Wire, Plain, for Concrete ReinforcementASTM C 144(2004) Standard Specification for Aggregate for Masonry MortarASTM C 270(2008a) Standard Specification for Mortar for Unit MasonryASTM E 119(2008a) Standard Test Methods for Fire Tests of Building Construction and Materials]1.2 SUBMITTALS
NOTE: Review submittal description (SD) definitions in Section 01 33 00 SUBMITTAL
PROCEDURES and edit the following list to reflect only the submittals required
for the project. Submittals should be kept to the minimum required for adequate
quality control.
A “G” following a submittal item indicates that the submittal requires Government
approval. Some submittals are already marked with a “G”. Only delete an existing
“G” if the submittal item is not complex and can be reviewed through the Contractor’s
Quality Control system. Only add a “G” if the submittal is sufficiently important
or complex in context of the project.
For submittals requiring Government approval on Army projects, a code of up
to three characters within the submittal tags may be used following the "G"
designation to indicate the approving authority. Codes for Army projects using
the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO"
for District Office (Engineering Division or other organization in the District
Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project
Office. Codes following the "G" typically are not used for Navy, Air Force,
and NASA projects.
Choose the first bracketed item for Navy, Air Force and NASA projects, or choose
the second bracketed item for Army projects.
Government approval is required for submittals with a "G" designation; submittals not having a "G" designation
are for [Contractor Quality Control approval.][information only. When used, a designation following the "G"
designation identifies the office that will review the submittal for the Government.] The following shall be
submitted in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:
SD-03 Product Data
Glass Block
Waterproofing Agent
Horizontal Joint Reinforcement
Panel Anchors
Expansion Strip
SD-04 Samples
Glass Block
Horizontal Joint Reinforcement
Panel Anchors
Expansion Strip
SD-07 Certificates
Glass Block
Certificates of compliance stating that the materials meet the specified requirements.
1.3 DELIVERY, STORAGE, AND HANDLING
Deliver cement, lime, and other cementitious materials to the site in unbroken containers, labeled with the manufacturers'
names and brands. Store mortar materials in a manner to prevent the inclusion of foreign materials and damage
by water or dampness. Avoid chipping and breakage of masonry units. Protect glass block materials from contact
with earth and exposure to the weather, and keep dry until used. Do not use materials containing frost or ice.
PART 2 PRODUCTS
2.1 GLASS BLOCK UNITS
NOTE: The desired physical characteristics (Light transmittance, reflectivity,
pattern, size, etc.) should be described. Drawings will clearly show the clearances
required for deflection and expansion.
Provide glass block units of type[s], size, pattern and style specified. Do not change source of supply for
material which will affect the appearance of the finished work after work has started. The Contractor shall
have on hand extra units amounting to [5] [_____] percent of the number of units incorporated in the work. Use
extra units to replace units found to be defective. Provide units made of clear colorless glass. Provide polyvinyl
butyral edge coating. Provide [75] [_____] percent light transmission allowance. Provide ventilators and accessories
recommended by glass block manufacturer.
2.1.1 Exterior Glass Block Units
Provide [DECORA] [VUE] [ARGUS] [_____] pattern [with LX] [without] fibrous glass insert, [_____] texture, sized
[197 by 197] [_____] by 98 mm [7-3/4 by 7-3/4] [_____] by 3-7/8 inches. Units designated as "reflective glass
block" shall have a highly reflective oxide surface coating of a [gray] [_____] color.
2.1.2 Interior Glass Block Units
Provide [VUE] [_____] pattern, [197 by 197] [_____] by 76 mm [7-3/4 by 7-3/4] [_____] by 3-1/8 inches.
2.1.3 Solid Glass Block Units
Units shall be [VISTABRIK] [_____], 194 by 194 by 76 mm 7-5/8 by 7-5/8 by 3 inches.
2.1.4 Fire Rated Glass Block Units
Walls and partitions indicated on the drawings to be fire rated and containing glass block units shall use approved
units that have been fire tested in accordance with ASTM E 119 to the indicated rating.
2.2 MORTAR
2.2.1 Mortar Mix
ASTM C 270, Type S, white portland cement.
2.2.2 Aggregates
ASTM C 144, clean, white quartzite type sand, not less than 100 percent passing a No. 8 sieve.
[2.2.3 Waterproofing
Provide metallic-stearate-type waterproofing agent. Omit waterproofing agent if portland cement containing waterproofing
agent is used.
]2.2.4 Admixtures
Do not use accelerators or anti-freeze compounds.
2.2.5 Prepackaged Mortar Mix
ASTM C 270, Type S, white portland cement.
2.3 ACCESSORIES
2.3.1 Horizontal Joint Reinforcement
Fabricate from cold drawn steel wire, ASTM A 82/A 82M. Wire shall be zinc coated after fabrication by the hot-dip
process conforming to ASTM A 153/A 153M, Class B-2. Reinforcement shall consist of two or more parallel longitudinal
wires not lighter than 9 gauge (3.40 mm 0.1483 inch) weld connected with cross wires not lighter than 14 gauge
(2.03 mm 0.0800 inch) at not greater than 200 mm 8 inches on center. Provide at least one longitudinal wire
for each face of glass block, out-to-out spacing approximately 37 mm 1-1/2 inches less than the actual width
of the block. Provide joint reinforcement in flat sections, not less than 2400 mm 8 feet long, except that corner
reinforcements and other special shapes may be shorter.
2.3.2 Panel Anchors
2.3.2.1 Strip Anchor
Perforated steel strip not less than 0.9 mm 20 gauge, minimum of 45 mm wide by 600 mm long 1-3/4 inches wide
by 24 inches long and galvanized after fabrication.
2.3.2.2 Wire-Type Anchor
Steel wire not less than 3.4 mm 9 gauge of approved design suitable for use with the panel stiffener provided
and galvanized after fabrication.
2.3.3 Expansion Strip
Dense fibrous glass batt or material as recommended by the glass block manufacturer.
2.3.4 Packing
Polyethylene foam, neoprene, or filler as recommended by the sealant manufacturer.
PART 3 EXECUTION
3.1 INSTALLATION
Do not lay glass block when the air temperature is 5 degrees C 40 degrees F and falling, or when it appears probable
that temperatures below 5 degrees C 40 degrees F will be encountered before the mortar has set, unless protection
is provided to prevent freezing. Protection shall consist of maintaining the temperature of glass block and
mortar materials between 5 and 50 degrees C 40 and 160 degrees F. After erection, maintain air temperature above
5 degrees C 40 degrees F on both sides of glass block for not less than 72 hours. Do not work with or on frozen
materials. Glass block work may be started at 1 degree C 34 degrees F on a rising thermometer. Coordinate glass
block work with the work of other trades to accommodate built-in items.
3.1.1 Workmanship
Carry glass block work up level and plumb all around. Build in window frames and doors as work progresses.
Handle glass block with care to avoid 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 anchors into adjacent masonry and concrete or welded to steel framing 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.
3.1.8 Tooling
After initial set of mortar, tool exposed joints and compress with a rounded jointer. Finished surface of joint
shall be slightly concave, smooth, and non-porous.
3.1.9 Packing and Sealing
After final set of mortar, provide packing in space between glass block panel head, jamb and intermediate support
construction and seal with sealant specified in Section 07 92 00 JOINT SEALANTS.
3.2 CLEANING
3.2.1 Protection
Protect work which may be damaged, stained, or discolored during cleaning operations.
3.2.2 Pointing
Upon completion of glass block work, cut out defective mortar joints and tuck point joints solidly with mortar.
3.2.3 Cleaning
Remove excess mortar from glass block with damp cloth or sponge before set occurs. Clean exposed surfaces with
clear water and stiff fiber brushes, and rinse with clear water. Where stains, mortar, or other soil remain,
continue cleaning with warm water and soap. Do not use abrasive cleaners (steel wool, wire brush) or acids in
conjunction with removing mortar or dirt from the glass block faces. Restore damaged, stained, or discolored
work to original condition or provide new work.