Installation Guide

6
Basecoat Plasters
Description
Gold Bond
®
Two-Way Hardwall
Plaster is a basecoat plaster which
requires the job site addition of an
aggregate and water to provide
working qualities and is designed
for interior use over all accepted
plaster bases. It may be applied by
hand or used through pump/ spray
plastering machines.
Features/Benefits
Controlled Uniformity
Two-Way Hardwall Plaster is set-
stabilized and adjusted for market
requirements and seasonal changes.
When mixed with sand or other
aggregate it has uniform working
qualities and excellent spread.
Technical Data
Strength
Two-Way Hardwall Plaster properly
proportioned with aggregate forms
a hard, durable base for the finish
coat. Its high tensile and compres-
sive strength results in increased
resistance to minor structural
movements, impacts and abrasions.
Fire Resistance
Two-Way Hardwall Plaster is
essentially mineral in composition
and will not support combustion.
Gold Bond
®
brand
Two-Way Hardwall Gypsum Plaster
Description
Gold Bond
®
Gypsolite
®
is a light-
weight gypsum basecoat plaster
mixed at the mill with correctly
sized and proportioned perlite
aggregate, requiring only the
addition of water on the job. It
is manufactured to be trowel-
applied over gypsum plaster base,
and in some cases metal lath
(see LIMITATIONS.)
Features/Benefits
Uniform Strength and
Hardness
Uniformity is assured through exact
proportioning and thorough mixing
of graded perlite and gypsum plas-
ter at the mill. Gypsolite provides a
uniform base for the finish coat.
Lightweight
Gypsolite weighs less than half
as much as sanded gypsum plas-
ter, thus reducing the dead-load
on framing.
High Insulating Value
Gypsolite has a “k” factor of 1.5
which provides about 3-1/2 times the
insulating value of sanded plaster.
Fire Resistance
Gypsolite has excellent fire-resistive
qualities and generally provides fire
ratings higher than sanded plaster.
Limitations
When used over metal lath, a sand
float finish should be specified. A
smooth-trowel finish is not recom-
mended since the combination of a
relatively soft (perlite aggregated)
basecoat and a hard (smooth-
trowel lime/gauging) finish has the
potential for cracking and spalling
of the finish coat.
Specification Reference
ASTM Designation C 28,
“Gypsum Plasters”.
Bag Weight
50 lbs. (22.7 kg)
25 lbs. (11.3 kg)
Specification Reference
ASTM Designation C 28,
“Gypsum Plasters”.
Bag Weight
50 lbs. (22.7 kg)
Gold Bond
®
brand
Gypsolite
®
Plaster
AGGREGATE PROPORTION AND ESTIMATED COVERAGE
Coverage, Sq. Ft. Thick-
Aggregate Sq. Yds. /Ton (Sq. M.) ness
Proportions Plaster Base ( Sq. M./Metric Ton ) per Bag In. (mm)
Sanded Gypsum Lath 88-110 40-50 7/16"
1:2-1/2 (80-102) (3-5) (11.1)
Sanded Gypsum Foil 88-110 40-50 7/16"
1:2-1/2 Back Lath (80-102) (3-5) (11.1)
Sanded Metal Lath 45-63 20-26 9/16"*
1:2-1/2 (42-58) (1.5-2.5) (14.3)*
Sanded Brick & Clay Tile 88-110 40-50 9/16"
1:3 Concrete Block (80-102) (3-5) (14.3)
*Measured from face of lath.
Note: Sanded 1:2-1/2 means 1 part plaster to 2-1/2 parts sand by weight.
Technical Data
GYPSOLITE ESTIMATED COVERAGE (50 LB. BAG)
Coverage, Sq. Ft. Thickness
Sq. Yds. per Ton (Sq. M.) In.
Plaster Base (Sq. M/Metric Ton) per Bag (mm)
Gypsum Lath and 90-100 32-35 7/16"
Gypsum Foil Back Lath (83-92) (3-3.5) (11.1)
Metal Lath 42-52 16-19 9/16"*
(39-48) (1.5-1.8) (14.3)*
*Measured from face of lath.
WEIGHT COMPARISON OF BASECOAT PLASTERS
Dry Set Mortar Weight Sanded 1:3 Gypsolite
Weight lbs. per cu. ft. (kg/m3) 120 (1922) 50 (801)
Lbs./yd.
2
(kg/m
2
) 3/8" (9.5 mm) thick 34 (18) 14 (8)
Lbs./yd.
2
(kg/m
2
) 1/2" (12.7 mm) thick 45 (24) 19 (10)
Lbs./yd.
2
(kg/m
2
) 5/8" (15.9 mm) thick 56 (30) 24 (13)
Lbs./yd.
2
(kg/m
2
) 3/4" (19.0 mm) thick 67 (36) 29 (16)
Wet Mortar Weight
Weight lbs. per cu. ft. (kg/m
3
) 140 (2243) 69 (1105)