GLASS-FIBER REINFORCED CEMENT (GRC)
PART 1- GENERAL
1.01 SUMMARY
A. Related sections:
1. Division 5, Metal Stud Framing
2. Division 7, Sealants
3. Division 9, Painting
1.02 REFERENCES
A. Standards of the following as referenced:
1. American Society for Testing and Materials (ASTM)
1.03 DEFINITIONS
A. Terms:
1. GRC -Glass-Fiber Reinforced Cement
2. GRC+ -Glass-Fiber Reinforced Cement w/ Sand
3. GRC- -Glass-Fiber Reinforced Cement w/o Sand
1.04 SUBMITTALS
A. Product Data:
1. Manufacturer’s literature
2. Material Safety Data Sheets for raw materials used to
produce GRC
B. Shop drawings:
1. Detailing GRC members; include locations, sizes and shapes
of members, proposed jointing arrangements, details of attachments,
suspension systems, and items pertinent to the GRC members.
2. Where applicable, show reflected ceiling plan.
3. Include plans at not less than ½” = 1’-0”,
details at not less than 3” = 1’-0” scale
4. Include manufacturer’s recommendations for storage,
handling, installation, and patching/finishing of GRC members.
C. Samples:
1. 6” x 6” flat samples depicting material thickness
and surface finish to be supplied.
D. Quality control submittals:
1. Test reports:
a. Test data from an approved independent testing laboratory
establishing compliance with specification requirements.
b. Tests to be performed by an independent testing agency
employed by the manufacturer of the finished product under
his own trade name. Include the following:
1) Flexural strength
2) Impact resistance
3) Hardness
4) Coefficient of linear thermal expansion
5) Humidified deflection
6) Flammability
7) Compressive strength
8) Dry and wet density
2. Certificates:
a. Manufacturer’s certification that all GRC pieces
contain at least 3% by weight of glass fiber reinforcement.
1.05 QUALITY ASSURANCE
A. Manufacturer’s Qualifications:
1. Obtain GRC from a manufacturer who will, upon request,
send a qualified technical representative to the project
site for the purpose of advising the installer of procedures
and precautions for materials used.
2. Obtain GRC from a manufacturer who will certify the materials
have been tested and proven satisfactory for the intended
use.
3. Obtain GRC from a manufacturer with five years verifiable
and successful experience producing material for projects
of similar size and scope.
4. GRC must be manufactured in the United States.
B. Installer’s Qualifications:
1. Firm must provide evidence of three years verifiable
evidence installing the specified work.
2. Installer must be acceptable to the manufacturer.
1.06 DELIVERY, STORAGE AND HANDLING
A. Deliver GRC members in packaging/crating required to
minimize damage in transit.
B. Upon receipt of each GRC shipment, unpack a random sampling
of each profile to verify GRC’s compliance with FABRICATION
Article. Repackage the material and do not unpack until
immediately prior to installation.
C. Store per the manufacturer’s written instruction.
1.07 SEQUENCING AND SCHEDULING
A. Coordinate the delivery and installation of GRC members
with work specified in other sections.
B. Do not proceed with the installation of GRC members until
conditions are acceptable.
1.08 WARRANTY
A. The GRC manufacturer and installing contractor shall
jointly warrant the GRC members to be free from defects
in materials and workmanship for one year from the date
of installation.
B. The warranty shall be based on installation methods in
accordance with the manufacturer’s recommendations
and instructions.
PART 2- PRODUCTS
2.01 MANUFACTURERS
A. Acceptable manufacturer:
First Class Building Products, Inc.
3600 Dallas Highway Suite 230-387
Marietta, GA 30064 (770-514-8141)
B. Any other manufacturer seeking approval must submit acceptable
test data, product literature, samples, and certificates
(per section 1.04) at least 14 days prior to the originally
scheduled bid date.
C. Characteristics
1. GRC to consist of DENS-CRETE EC cement as manufactured
be Georgia-Pacific Corporation, water, polymer, and type
‘E’ glass fiber mat.
2. GRC+ will also contain silica sand.
3. GRC- will not contain silica sand.
4. GRC+ will have a design thickness of 7/16” and
a design weight of approx. 3.5 psf.
5. GRC- will have a design thickness of ¼”
and a design weight of approx. 2 psf
6. Flexural Strength
ASTM test method C947
Flexural yield -1871psi
Flexural ultimate -3075 psi
7. Impact Resistance
ASTM test method D256, Method E (Izod reverse notch method)
10.2
8. Hardness
ASTM test method D2583
Barcol Hardness of 74 Shore D-2
9. Coefficient of Linear Thermal Expansion
ASTM test method D696
0.00000853 in/in degrees Centigrade
10. Humidified Deflection
ASTM test method C473
0.049 in.
11. Compressive Strength
ASTM test method C109
3070 psi
12. Density
Dry Bulk Density -86.93 lbs. / cu. ft.
Wet Bulk Density -113.78 lbs. / cu. ft.
13. Flammability
ASTM test method E84-94
Flame Spread Index -5
Smoke Developed Value -0
2.02 ACCESSORIES
A. Fasteners, embeds, and framing as detailed in the approved
shop drawings.
B. Fasteners to be non-corrosive, non-bleeding.
C. Adhesive to be silicone based.
2.03 FABRICATION
A. Fabricate GRC members to profiles, shapes, and configurations
detailed on approved shop drawings using manufacturer’s
standard processes.
B. Tolerances as stated on manufacturer’s approved
shop drawings.
C. Finished surfaces to have a smooth finish suitable for
priming
PART 3- EXECUTION
3.01 INSTALLATION, JOINT FINISHING AND PIMING
A. Comply with the manufacturer’s written storage,
handling, installation, and patching/finishing instructions
as well as the approved shop drawings.
B. Finish the indicated joints at piece intersections such
that joints are neither visible nor perceptible.
C. Priming
1. All GRC material should be primed with one or more coats
of:
Sheboygan Paint Company
Cedartown, GA
(770) 748-8426
Product No. 43-1685
Off White Concrete Sealer
2. Sanding after each coat of primer may be required.
