U.S. General Services Administration
Technical Procedures Disclaimer
Prior to inclusion in GSA’s library of procedures, documents are reviewed by one or more qualified preservation specialists for general consistency with the Secretary of Interior Standards for rehabilitating historic buildings as understood at the time the procedure is added to the library. All specifications require project-specific editing and professional judgement regarding the applicability of a procedure to a particular building, project or location. References to products and suppliers are to serve as a general guideline and do not constitute a federal endorsement or determination that a product or method is the best or most current alternative, remains available, or is compliant with current environmental regulations and safety standards. The library of procedures is intended to serve as a resource, not a substitute, for specification development by a qualified preservation professional.
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We’ve reviewed these procedures for general consistency with federal standards for rehabilitating historic buildings and provide them only as a reference. Specifications should only be applied under the guidance of a qualified preservation professional who can assess the applicability of a procedure to a particular building, project or location. References to products and suppliers serve as general guidelines and do not constitute a federal endorsement nor a determination that a product or method is the best alternative or compliant with current environmental regulations and safety standards.
REMOVING AND REPLACING STRUCTURAL GLASS WALL PANELS
PART 1–GENERAL
1.01 SUMMARY
A. This procedure includes guidance on removing damaged
structural glass panels and replacing with salvaged or
new panels.
B. See 01100-07-S for general project guidelines to be
reviewed along with this procedure. These guidelines
cover the following sections:
1. Safety Precautions
2. Historic Structures Precautions
3. Submittals
4. Quality Assurance
5. Delivery, Storage and Handling
6. Project/Site Conditions
7. Sequencing and Scheduling
8. General Protection (Surface and Surrounding)
These guidelines should be reviewed prior to performing
this procedure and should be followed, when applicable,
along with recommendations from the Regional Historic
Preservation Officer (RHPO).
PART 2–PRODUCTS
2.01 MANUFACTURERS
USG Corporation
www.usg.com
2.02 MATERIALS
NOTE: Chemical products are sometimes sold under a common
name. This usually means that the substance is not as pure as
the same chemical sold under its chemical name. The grade of
purity of common name substances, however, is usually adequate
for stain removal work, and these products should be purchased
when available, as they tend to be less expensive. Common
names are indicated below by an asterisk (*).
A. Structural glass to match existing
B. Solvent for Removing Adhesive:
1. Methyl Ethyl Ketone:
a. Other chemical or common names include 2-butanone; MEK*.
b. Potential Hazards: TOXIC AND FLAMMABLE.
c. Available from chemical supply house, hardware
store or paint store.
-OR-
2. Methyl Isobutyl Ketone:
a. Other chemical or common names include
Asymmetric ethyl methyl acetone; 3-methyl-2-
pentanone; Secondary butylmethyl ketone;
MIBK*.
b. Potential Hazards: TOXIC AND FLAMMABLE.
c. Available from chemical supply house, hardware
store or paint store.
-OR-
3. Acetone (C3H6O):
a. A volatile fragrant flammable liquid ketone
used chiefly as a solvent and in organic
synthesis and found abnormally in urine.
b. Other chemical or common names include
Dimethyl ketone; Propanone
c. Potential Hazards: VOLATILE AND FLAMMABLE
SOLVENT
d. Available from chemical supply house or
hardware store.
C. Stainless steel wire - 1 gauge
D. Petroleum-based adhesive appropriate for installing structural glass panels
as recommended by glass manufacturer or approved equal.
E. Water-based glass cleaner
F. Grout to match existing such as moulding plaster (USG Corporation)
or approved equal.
G. Clean, potable water
2.03 EQUIPMENT
A. Mudpan for mixing grout
B. Squeeze bottle for applying solvent
C. Metal scraper
D. Stiff bristle brush (non-metallic)
E. Clean, dry cloths
F. Hard, rubber trowel
PART 3–EXECUTION
3.01 ERECTION, INSTALLATION, APPLICATION
A. Remove damaged or broken structural glass panels.
1. Rake and remove grout from joint surrounding piece
to be removed.
2. Using a squeeze bottle, apply solvent to back of
panels to be salvaged and allow mastic to soften.
3. Cut the softened mastic with the stainless steel
wire and remove the panel from the wall.
4. Use solvent and metal scraper to remove remaining
mastic from the back of structural glass panel.
B. Install New or Salvaged Structural Glass Panels:
1. Using a stiff bristle brush, remove dirt and debris
from the surface. Using a metal scraper, remove
any remaining adhesive.
2. Apply adhesive to back of panel and install to
match coursing lines and grout joint widths.
3. Support glass for at least 24 hours until the
adhesive has cured.
C. Remove mastic from adjacent surfaces using a clean cloth
and a solvent.
D. Mix enough grout for 1 hour supply at a time. Add enough
water to form a workable consistency.
E. Trowel grout flush into joints. Take care not to scratch
the structural glass surface.
F. Allow the grout to cure for 72 hours, keeping them damp
during that period.
G. Gently rinse the surface with water and a stiff bristle
brush.
H. Clean the surface with glass cleaner and a soft, clean
cloth.