LEVELS
OF GYPSUM BOARD FINISH
LEVEL
1 -
Tape set in joint compound.
Tool marks and ridges acceptable.
Surface is free of excess joint compound.
Suggested
use:
Frequently specified in areas above
ceilings, in attics, in areas where the assembly would generally be
concealed, or in areas not normally open to public view.
Some degree of sound and smoke control is provided.
In some geographic areas, this level is referred to as
"fire-taping". Tape and
fastener heads need not be covered with joint compound.
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LEVEL
2 -
Tape
embedded in joint compound and wiped with a joint knife, leaving a thin
coat of compound over tape.
Surface shall be covered by one separate coat of joint compound.
Surface shall be free of excess joint compound.
Tool marks and ridges acceptable.
Joint compound applied over the body of the tape at the time of
tape embedment shall be considered a separate coat of joint compound and
shall satisfy the conditions of this level.
Suggested
use:
Specified where water-resistant gypsum backing board is used as a
substrate for tile. May also
be specified in garages, warehouse storage or other similar areas where
surface appearance is not of primary concern.
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LEVEL 3 -
Taped as in level #2, then covered with
two separate coats of joint compound.
Joint compound shall be smooth and free of tool marks and ridges.
Note: It is recommended
that the prepared surface be coated with a drywall primer prior to the
application of final finishes.
Suggested
use:
Typically specified in appearance areas which are to receive heavy
or medium texture finishes before final painting, or where heavy-grade
wall coverings are to be applied as the final decoration.
This level of finish is not recommended where smooth painted
surfaces, or light to medium weight wall coverings are specified.
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LEVEL
4 -
Taped as in level #2, then covered with
three separate coats of joint compound.
Joint compound shall be smooth and free of tool marks and ridges.
Note: It is
recommended that the prepared surface be coated with a drywall primer
prior to the application of final finishes.
Suggested
use:
This
level should be specified where flat paints, light textures or wall
coverings are to be applied.
In critical lighting areas, flat paints applied over light textures tend
to reduce joint photographing.
Gloss, semi-gloss and enamel paints are not recommended over this
level of finish. The weight,
texture and sheen level of wall coverings applied over this level of
finish should be carefully evaluated.
Joints and fasteners must be adequately concealed if the wall
covering material is lightweight, contains limited pattern, has a gloss
finish or any combination of these features is present.
Un-backed vinyl wall-coverings are not recommended over this level
of finish.
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LEVEL
5 -
Taped as
in level #4. Surface shall be
covered by three separate coats of joint compound.
A thin skim coat of joint compound, or a material manufactured
especially for this purpose, shall be applied to the entire surface.
The surface shall be smooth and free of tool marks and ridges.
Note: It is
recommended that the prepared surface be coated with a drywall primer
prior to the application of final finishes.
Suggested
use:
This
level of finish is highly recommended where gloss, semi-gloss, enamel or
non-textured flat paints are specified, or where severe lighting
conditions occur. This
highest quality finish is the most effective method to provide a uniform
surface and minimize the possibility of joint photographing and of
fasteners showing through the final decoration.
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GLOSSARY
Critical
Lighting - Strong sidelighting from windows or surface-mounted light fixtures.
Wall and ceiling areas abutting windows or skylights, long hallways, or
atriums with large surface areas flooded with artificial and/or natural
lighting are a few examples of critical lighting areas. Strong
sidelighting from windows or surface-mounted light fixtures may reveal
even minor surface imperfections. Light striking the surface
obliquely, at a very slight angle, greatly exaggerates surface
irregularities. If critical lighting cannot be avoided, the effects
can be minimized by skim coating the gypsum board surfaces, by decorating
the surface with medium to heavy textures, or by the use of draperies and
blinds which soften shadows. In general, gloss, semi-gloss, and
enamel finishes highlight surface defects; textures hide minor
imperfections.
Drywall Primer
- A paint material specifically formulated to fill the pores and equalize
the suction difference between gypsum board surface paper and the compound
used on finished joints, angles, fastener heads, and accessories and over
skim coatings.
Skim Coat - Either a thin coat of joint compound applied or a material manufactured
especially for this purpose and applied in accordance with manufacturer's
recommendations, over the entire surface. A skim coat is intended to
conceal small imperfections in joints and on the surface of the gypsum
board, smooth the texture of the paper, minimize differences in surface
porosity, and create a more uniform surface to which the final decoration
can be applied. There is no specific mil thickness that constitutes
a proper skim coat. A skim coat will not approximate a plastered
surface. Once the skim coat dries, the gypsum board paper may show
through and the treated joints, filled voids, and spotted fastener heads
will likely be visible.
Texturing - Regular or irregular patterns typically produced by applying a mixture
of joint compound and water, or proprietary texture materials including
latex base texture paint, to a gypsum board surface previously coated with
drywall primer. Texture material is applied by brush, roller, spray,
trowel, or a combination of these tools, depending on the desired result.