Lather
Skill Trades 1201
Introduction

Lathers
 Assemble
and install the framework for
gypsum materials (Drywall & Plaster) in
buildings.
Plasters

Two main types:
1. Cement based - Used mainly for outdoors.
2. Gypsum based – Indoors only.
Cement Based

Can be used indoors for areas that

Are likely to become damp and
 Require a greater thickness of cover.
Gypsum Based
Used in conjunction with drywall to cover
the interior walls.
 Can be powder form which must be mixed
with water, or Premixed and ready for use.

Drywall Joint Compound

Two categories:
1. Drying-type compounds
2. Setting-type compounds
Drying Type Compound
The most common compound
 Pre-mixed or Powdered form
 Dry via water evaporation
 Allow 24 hours for drying

Drying Type Compound

Three kinds of drying type compound:
1. Topping compound:
Final thin coat,
 Ease of workability

Drying Type Compound
2. Taping compound:
First coat to capture the joint tape
 Second coat as filler

Drying Type Compound
3. All-purpose compound:
Any stage of drywall joint taping.
 It is the most commonly used

Setting Type Compound
Dries by chemical reaction
 Hardens much quicker (20 mins to 6 hrs).
 Harder to sand.
 Does not come premixed

Drywall

Drywall

Sheet material made of a sandwich of
gypsum and two layers of paper.
Drywall sizes

Width
4

feet
Length
 8,

10 or 12 feet
Commercial builders often use sheets up to 16
feet in length.
Drywall Thickness

5/8 inch panel:
 Considered
fire resistant.
Drywall Thickness

1/2 inch panel:
 Most
commonly used
 General purpose for walls and ceilings.
Drywall Thickness

1/4 - 3/8 inch panel
 Used
sometimes to overlay existing, older
walls in order to make it smoother.
 Is also used to make curved walls.
Types of Drywall

Standard drywall sheets
 Have
tapered long edges and the short ends
are squared off.
 One face is rough, and one face is smooth,
for painting and papering.
Types of Drywall

Moisture Resistant Board
 Also
known as Greenboard.
 Used in interior areas such as bathrooms and
basements where added moisture resistance is
needed.
Types of Drywall

Fire Rated
 5/8
drywall.
 Used between apartments.
Fasteners

Screws
 Type

W bugle head screws
Has a course thread and provides excellent holding power in
wood.
Screws cont’d.

Type S bugle head screws
 Has
a tip that drills its own hole in metal studs in
walls.
Fasteners

Nails
 Ringed-Shank


nails
The rings provide better grip.
Provides 50 to 100 percent greater holding power than a
smooth-shank nail.
Drywall Tape

Drywall tape is used to cover or seal the joins
between drywall edges.
Drywall Tape

Types
 Flexible Paper
The paper tape is applied into wet plaster.
 Crease in centre so it can be folded.

Drywall Tape

Fiberglass Mesh Fabric - The mesh is
usually self adhesive.
Drywall Tools
6. Sanders: used to smooth the plaster before paint is applied.
Installing Drywall
Drywall is always fastened to the ceiling
before the walls.
 Drywall is fastened to the “studs” of the
walls.

Ceiling
Walls