Upload
alexander-mamani
View
222
Download
0
Embed Size (px)
Citation preview
7/28/2019 Drywall Powerpoint0
1/27
Lather
Lathers assemble and install the framework for gypsum
materials in buildings. These materials include drywall and
plaster.
7/28/2019 Drywall Powerpoint0
2/27
Plaster and plastering
There are quite a few plasters but two main types - gypsum based and cement
based.
1. Cement based are used mainly for outdoors.
2. Gypsum based plasters are used indoors only - dampness will attack a gypsum
based plaster and cause it to crumble.
Cement based plasters can be used indoors for areas that are likely to become dampand areas that require a greater thickness of cover.
Gypsum based plaster is used in conjunction with drywall to cover the interior
walls of our homes. This plaster can be found as a powder which must be mixed
with water, or premixed and ready for use.
7/28/2019 Drywall Powerpoint0
3/27
What is Drywall?
Drywallsometimes called wallboard, plasterboard, or the brand name
Sheetrockis comprised of a core of wet gypsum rock that is sandwiched
between two sheets of heavy paper. When the gypsum core sets and dries,
the finished product is rigid and sturdy enough for use as a building
material. Drywall is called such because it is a dry alternative to the
previously used lath and plaster method of wall construction, where plasterwas spread over wood formers while still wet. Drywall is faster, less labour
intensive, and cheaper to install than plaster.
7/28/2019 Drywall Powerpoint0
4/27
Drywall sizes
Standard drywall comes in sheets that are four feet wide, with lengths of
eight, ten, or twelve feet. Commercial builders often use sheets up to sixteenfeet in length. These large sheets make for quicker installations, because they
reduce the number of joints (seams) between the sheets that need to be filled and
finished.
7/28/2019 Drywall Powerpoint0
5/27
Panel thickness:
5/8 inch panel-
considered fire resistant. Even though drywall generally does not burn, 5/8 inch
drywall is used as a firewall. For example, a house that has an adjoining
apartment, 5/8 inch drywall must be used on the wall that the two residencesshare (common wall), and acts as a fire wall. It prevents the fire from spreading
from one residence to the other.
1/2 inch panel-
most commonly used. General purpose for walls and ceilings.
7/28/2019 Drywall Powerpoint0
6/27
7/28/2019 Drywall Powerpoint0
7/27
Types of Drywall
Dent resistant - found in 1/2 inch or 5/8 inch. Much more durable than
regular drywall. Used in high traffic areas, childrens
playrooms, garage, etc.
Sag resistant- found in 1/2 inch panels. Will not sag like some other
1/2 inch panels.
Good to use on ceilings.
7/28/2019 Drywall Powerpoint0
8/27
Sound control board- used to reduce sound and also offers higher
thermal insulation. Found in 1/2, 5/8, 3/4 inch
panels.
Cementious backerboard- cement product reinforced with fiberglass
mesh. Used on walls that may be exposed to
water, such as showers.
7/28/2019 Drywall Powerpoint0
9/27
Fasteners
Screws
1. Type W bugle head screws
- has a course thread and provides excellent holding power in wood.
2. Type S bugle head screws
- has a tip that drills its own hole in metal studs in walls.
3. Backerboard screws
- made from stainless steel or steel that is non-corrosive
7/28/2019 Drywall Powerpoint0
10/27
Fasteners contd
nails
- both smooth and ringshank nails are used. The smooth nails do not hold the
drywall as secure as the ringshank nails. The rings on the shank of the nail gets abetter grip in the wood, thus decreasing the number of nail pops (when the nail
starts to come back out of the drywall).
7/28/2019 Drywall Powerpoint0
11/27
Once the drywall has been secured to the wall studs, the seams or joins are
to be covered with plaster before the paint is applied. Before the plaster
can be applied to the joins, it must be covered with tape or beads. Tape
and beads come in a variety of types:
1. Flexible paper tape:
Usually has a seam running along its length so that it can be folded to be
used in corners. Tends to be more time consuming because it has to be
embedded in a coat of plaster.
7/28/2019 Drywall Powerpoint0
12/27
2. Fiberglass mesh tape:
Usually self sticking. Its not necessary to apply a coat of plaster underneath it.
3. Composite and metal tapes:
Since these tapes are rigid, it makes it much easier to get a straight crisp inside
corner.
4. Bullnose and metal corners:
These enable you to create a straight and neat outside corner. The metal corner
is a 90 degree angle, whereas the bullnose corner is rounded.
Plaster must be applied to the edges of both inside and outside corners so that it
appears seamless once painted.
7/28/2019 Drywall Powerpoint0
13/27
Tapes
7/28/2019 Drywall Powerpoint0
14/27
Common Drywall Tools
1. Utility knife: used for cutting drywall.
2. Drywall Saw: used for making cut-outs in the drywall
(circular, rectangular, etc.)
3. Metal snips: use for cutting metal corner beads.
7/28/2019 Drywall Powerpoint0
15/27
4. Screwgun: used for inserting screws into the drywall and studs. It is
different from other power drills because it limits the
depth that the screw goes into the drywall.
5. Trowels and taping knives: used to spread the plaster over the
drywall joins.
7/28/2019 Drywall Powerpoint0
16/27
6. Sanders: used to smooth the plaster before paint is applied.
7/28/2019 Drywall Powerpoint0
17/27
7. Water filter system: consists of a vinyl hose connected to a vacuum
cleaner on one end and a bucket on the other
end with water in it. Another hose leaves the
bucket and attaches to a sander. The idea is for
the dust from the sander to be vacuumed into t
he bucket depositing the plaster dust into the
water and not affecting the vacuum.
7/28/2019 Drywall Powerpoint0
18/27
Installing drywall on ceilings and walls
Drywall is always fastened to the ceiling before the walls. This ensures
that the drywall that goes on the wall is underneath the ceiling drywall
and helps to support the drywall thats on the ceiling.
Drywall is fastened to the studs of the walls. Studs are spaced either 16
inches or 24 inches on center. The studs provide the strength for the wall.
16 inch
centers24 inch
centers
7/28/2019 Drywall Powerpoint0
19/27
Ceiling
7/28/2019 Drywall Powerpoint0
20/27
Walls
7/28/2019 Drywall Powerpoint0
21/27
Plastering Seams and Joins
The following is the sequence of events that is usually followed when
plastering a join between two pieces of drywall:
1. If tape is being used, run a coat of plaster on the join.
7/28/2019 Drywall Powerpoint0
22/27
Plastering Seams and Joins
The following is the sequence of events that is usually followed when
plastering a join between two pieces of drywall:
1. If tape is being used, run a coat of plaster on the join.
2. Place a piece of tape over the plaster, along the full length of the join.
7/28/2019 Drywall Powerpoint0
23/27
Plastering Seams and Joins
The following is the sequence of events that is usually followed when
plastering a join between two pieces of drywall:
1. If tape is being used, run a coat of plaster on the join.
2. Place a piece of tape over the plaster, along the full length of the join.
3. Drag the plaster knife along the tape to allow the excess plaster to
squeeze out. Be careful not to tear the tape. Allow to dry.
7/28/2019 Drywall Powerpoint0
24/27
Plastering Seams and Joins
The following is the sequence of events that is usually followed when
plastering a join between two pieces of drywall:
1. If tape is being used, run a coat of plaster on the join.
2. Place a piece of tape over the plaster, along the full length of the join.
3. Drag the plaster knife along the tape to allow the excess plaster to
squeeze out. Be careful not to tear the tape. Allow to dry.
4. Apply a wider coat of plaster over the tape with a plaster knife. Allow to
dry.
7/28/2019 Drywall Powerpoint0
25/27
Plastering Seams and Joins
The following is the sequence of events that is usually followed when
plastering a join between two pieces of drywall:
1. If tape is being used, run a coat of plaster on the join.
2. Place a piece of tape over the plaster, along the full length of the join.
3. Drag the plaster knife along the tape to allow the excess plaster to
squeeze out. Be careful not to tear the tape. Allow to dry.
4. Apply a wider coat of plaster over the tape with a plaster knife. Allow to
dry.
5. Apply a third coat of plaster over the dry coat with a larger plasteringknife, feathering the edges (thinning the edges).
7/28/2019 Drywall Powerpoint0
26/27
Plastering Seams and Joins
The following is the sequence of events that is usually followed whenplastering a join between two pieces of drywall:
1. If tape is being used, run a coat of plaster on the join.
2. Place a piece of tape over the plaster, along the full length of the join.
3. Drag the plaster knife along the tape to allow the excess plaster to
squeeze out. Be careful not to tear the tape. Allow to dry.
4. Apply a wider coat of plaster over the tape with a plaster knife. Allow to
dry.
5. Apply a third coat of plaster over the dry coat with a larger plasteringknife, feathering the edges (thinning the edges).
6. Sand with fine sandpaper to smooth irregularities in preparation for
primer and paint.
7/28/2019 Drywall Powerpoint0
27/27
Plastering
Profile of layers
First coat over tape Second coat Third coat