Plastering techniques for buildings - external

1. EXTERNALPLASTERING
PRESENTED BY:
RAKHI DEV
RASHMI. R
SUNIDHI MADHAV
SWATHE

2. INTRODUCTION
 Plasterwork refers to construction or ornamentation
done with plaster, such as a layer of plaster on an
interior or exterior wall structure, or plaster decorative
mouldings on ceilings or walls.
 This is also sometimes called pargeting.
 The process of creating plasterwork,
called plastering, has been used in building
construction for centuries.
 The earliest plasters known to us were lime-based.
Around 7500 BC, the people of 'Ain Ghazal in Jordan
used lime mixed with unheated crushed limestone to
make plaster which was used on a large scale for
covering walls, floors, and hearths in their houses

3. TOOLS AND MATERIALS
 Tools and materials include trowels,
floats, hammers, screeds, a hawk, scratching
tools, utility knives, laths,
lath nails, lime, sand, hair,plaster of Paris, a
variety of cements, and various ingredients to
form color washes.

4. LATH
Lath seen from the back with brown coat oozing through

5.  Traditionally, plaster was laid onto laths, rather
than plasterboard as is more commonplace
nowadays.
 Wooden laths are narrow strips of straight-grained
wood depending on availability of species in lengths
of from two to four or five feet to suit the distances
at which the timbers of a floor or partition are set.
STUCCO
PEBBLEDASH
• Two predomiatly used
materials for Exteral plasterig

6. STUCCO
INTRODUCTION
Stucco is a term loosely applied to nearly all kinds of external plastering,
whether composed of lime or of cement. At the present time it has fallen into
disfavor, but in the early part of the 19th century a great deal of this work was
done.
Stucco from the House of
Borujerdi-ha
1850s, Kashan, Iran.

7. PREPARATION
 Traditional stucco is made of lime, sand, and water.
Modern stucco is made of Portland cement, sand,
and water.
 Lime is added to increase the permeability and
workability of modern stucco.
 Additives such as acrylics and glass fibers are
added to improve the structural properties of the
stucco.
 This is usually done with what is considered a one-
coat stucco system, as opposed to the traditional
three-coat method.

8. SCRATCH COAT
BROWN COAT
FINAL COAT
THREE ESSENTIAL COATS

9. SCRATCH COAT

10. Wire mesh holds row coat I
place

11. ROUGH TROWELLED
COLOUREDBASTARD

12. ROUGH STUCCO

13. ARCHITECTURAL VARIETY
 Stucco relief was used in the architectural
decoration schemes of many ancient cultures.
Examples of Egyptian, Minoan, andEtruscan stucco
reliefs remain extant. In Roman art of the late
Republic and early Empire, stucco was used
extensively for the decoration of vaults.
 Indian architecture knows stucco as a material for
sculpture in an architectural context. It is rare in the
countryside.
 Stucco is used to form a semi-plastic extension of
the real architecture that merges into the painted
architecture.

15. PEBBLEDASH OR ROUGHCAST
 INTRODUCTION – rough form of external
plastering in much use for country houses. In
Scotland it is termed "harling". It is one of the oldest
forms of external plastering.
 In Tudor times it was employed to fill in between the
woodwork of half-timbered framing.

16. ARCHITECT C F A VOYSEY  PIONEERED THE USE OF
PEBBLEDASH IN THE LATE 19TH AND EARLY 20TH
CENTURY
 Consists of lime and sometimes cement mixed
with sand, small gravel, and
often pebbles or shells.
 The materials are mixed into a slurry and are then
thrown at the working surface with a trowel or
scoop.

17. DRY DASH
Plasterer throwing pebble spars, aggregates or gravel into a wet top coat
render this gives a decorative finish

19. WET DASH
The undercoat is left to cure and in the final coat the gravel/aggregate is mixed
with the lime and sand and thrown on with the plaster spoon/scoop.

21. PEBBLEDASHING HELPS KEEP HEAT IN THE
HOME

22. ARCHITECTURAL VARIETY
A Tudor style semi in Brook Street, Port Sunlight by Grayson and Ould
(1906), with leaded lights, clay tile hangings over a pebbledash ground
floor and tall pebbledash chimneys. In this case the mortar used for the
pebbledash has the yellow-brown colour derided by Alec Clifton-Taylor.

23. Les Bois des Moutiers at Varengeville-sur-Mer, Edwin Lutyens’
supreme example of pebbledash on a grand scale. (Photo:
Michel Guilly)

24. A terrace in
Central Road,
Port Sunlight by
Garnett, Wright
and Barnish
(1907), with grey
cement
pebbledash on the
first floor gables.
Parapets and
Queen Anne
gables such as
these are
particularly
vulnerable to
damp penetration,
causing saturation
and the loss of the
pebbledash
through frost
damage.

25. ADVANTAGES AND DISADVANTAGES