Specification

ManualsBrandsUSG ManualsPaintStructo-Lite 50 lb. Basecoat Plaster

Description

TRUCTO-LITE

BRAND Basecoat is a mill-mixed perlite-aggregate gypsum plaster. It requires only the addition of

water at the jobsite.

TRUCTO-LITE

Basecoat is USG’s lightest-weight and most highly insulated plaster.

TRUCTO-LITE Basecoat provides a plastic working material that will conform to various designs and help

achieve durability in walls and ceilings. It can be applied by hand or machine methods, on gypsum or metal lath,

clay tile, concrete or cinder blocks and other approved plaster bases.

Fire Protection Gypsum plasters specially made for ﬁre-protection applications and used with speciﬁed plaster

bases, provide excellent ﬁre protection.

Sound Isolation In certain systems, gypsum plasters offer sound transmission loss characteristics suitable for

most requirements. Sanded basecoat plaster provides optimum results.

Control of Set STRUCTO-LITE Basecoat is formulated for use in varying climatic conditions and job conditions. The

quicker a gypsum plaster sets, the stronger the basecoat.

Limitations 1. Not recommended over metal lath when a smooth trowel ﬁnish is required.

2. Not recommended for machine application when vertical lift exceeds 30 ft. or hose length is over 150 ft.

3. Requires a lime-gauging ﬁnish plaster containing a ﬁne aggregate to control surface cracking.

4. Over interior monolithic concrete, USG

™

Plaster Bonder must be applied before plastering.

5. Application on masonry or concrete walls, or ceilings that have been coated with bituminous compounds or

other waterprooﬁng agents, is not recommended. The interior surface of exterior walls should be furred and

lathed prior to plastering to prevent seepage and condensation.

6. Basecoat plasters must not die or stop against a hollow metal doorframe return. Provision must be made to

dampen the trim return vibration by grouting, and by the use of special anchors. The grout must be raked out

to allow lath and plaster to be inserted into the frame.

7. Gypsum plasters cannot be used in exterior applications or where they will come into contact with water or

excessive moisture.

Directions Preparation In cold weather, all glazing should be completed and the building heated to a minimum 55 °F (13 °C) before

gypsum base or lath and plaster installation. The temperature of the building must be maintained in uniform

range above 55 °F for an adequate period prior to application of plaster, while plastering is being done, and until

plaster is dry. Heat should be well distributed in all areas, with deﬂection or protective screens used to prevent

concentrated or irregular heat on the plaster surfaces.

Ventilation and air circulation should be provided to properly dry the plaster subsequent to plaster applications

and proper set. This can be accomplished by keeping windows open sufﬁciently to provide air circulation in

glazed buildings; in enclosed areas lacking normal ventilation, provisions must be made to mechanically remove

moisture-laden air.

If glazed sashes are not in place and the building is subject to hot, dry winds or temperature differentials

from day to night of 20 °F (11 °C) or more, openings must be screened with cheesecloth or similar material.

Application Mixing Conventional Plaster S

TRUCTO-LITE Basecoat contains mill-mixed aggregate, so it is mixed with water only

on the jobsite. Mix basecoat plaster by hand or in a mechanical mixer to a uniform consistency. Use potable

(drinkable) water and clean mixing tools. Plaster can be mixed using a heavy-duty power drill equipped with

a mixing paddle, or a professional-style self-contained mixer. Water usage is approximately 12 to 15 quarts

(3 to 3.75 gallons) per 50 lb. bag. Sift plaster into water and blend with power agitator. Mix initially to a heavy

(stiff) viscosity to disperse the powder into the water. Mix until smooth and lump-free, then add any remaining

water to obtain the desired consistency. DO NOT retemper.

Submittal Sheet

09210

Structo-Lite

Basecoat

Where a lightweight, high-thermal-conductivity conventional plaster application is desired

– Mill-mixed perlite-aggregate gypsum plaster; requires only the addition of water at the jobsite.

– Ideal where it is not desirable to mix aggregate with plaster on the job.

– Lightweight plaster; weighs less than half as much as sanded plaster.

– Excellent for areas requiring highly insulated plaster; provides “k” factor of 1.74, three times the insulation

value of sanded plaster.

Summary of content (2 pages)

PAGE 1
Submittal Sheet 09210 Structo-Lite Basecoat ® – – – – Where a lightweight, high-thermal-conductivity conventional plaster application is desired Mill-mixed perlite-aggregate gypsum plaster; requires only the addition of water at the jobsite. Ideal where it is not desirable to mix aggregate with plaster on the job. Lightweight plaster; weighs less than half as much as sanded plaster. Excellent for areas requiring highly insulated plaster; provides “k” factor of 1.
PAGE 2
Applying Basecoat Apply the basecoat plaster by hand or machine in one or two coats. Unit masonry surfaces that exhibit high suction shall be moderately wetted immediately before plastering. For two-coat work over gypsum lath and masonry, apply STRUCTO-LITE Basecoat (first coat) with sufficient material and pressure to form a good bond to the base and to cover well; then double-back to bring the plaster out to grounds.