Lath and Plaster Flashcards
plaster:
materials
gypsum and lime, aggregates of sand, vermiculite or perlite, and water.
plaster application:
over base material in 2 or 3 coats.
plaster vs stucco
plaster = interior
stucco = exterior
plaster types:
vermiculite or perlite used for
lightweight, fire-resistant.
plaster types:
Keene’s cement
high resistant to abrasion and water penetration.
Stucco:
materials
portland cement, lime, sand and water.
stucco pros:
hard, non-water-absorbent.
portland cement: use
used as a backing for tile walls,
and the scratch and brown coats under Keene’s cement.
plaster application:
metal lath attached to metal or wood studs.
scratch coat:
brown coat:
finish coat:
scratch coat:
¼”, first coat over lath, flows around and behind open mesh.
brown coat:
¼”, layer 2.
finish coat:
⅛”, layer 3.
two coat plaster work combines
scratch and brown.
type of metal lath:
general purpose flat/curved surfaces.
expanded diamond mesh
type of metal lath:
asphalt-impregnated paper,
base for portland cement plaster under ceramic tile.
paper-backed diamond mesh
type of metal lath:
typ used for base for portland cement plaster under ceramic tile.
paper-backed diamond mesh
type of metal lath:
more rigid bc one-way, V-shaped ribs 4” o.c.
use: ceilings and solid partitions
flat-rib lath:
gypsum lath:
advantage
reduces labor bc only 1 coat needed
16x48” boards applied horizontally to studs,
or comes in 48x96” sheets.
gypsum lath
plaster and lath edges:
for outside corners
corner beads
plaster and lath edges:
to trim doors, windows
casing beads
stucco req’s expansion joints every
10 ft
veneer plaster walls fire rating
1-2hrs
