Externalplastering

EXTERNALPLASTERING

PRESENTED BY:

RAKHI DEV

RASHMI. R

SUNIDHI MADHAV

SWATHE

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

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.

LATH

Lath seen from the back with brown coat oozing through

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

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.

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.

SCRATCH COAT

BROWN COAT

FINAL COAT

THREE ESSENTIAL COATS

SCRATCH COAT

Wire mesh holds row coat I place

ROUGH TROWELLED

COLOUREDBASTARD

ROUGH STUCCO

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.

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.

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.

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

WET DASHThe 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.

PEBBLEDASHING HELPS KEEP HEAT IN THE HOME

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.

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

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.

ADVANTAGES AND DISADVANTAGES