EXTERNAL WALL FINISHES
Name : DIGVIJAY ADHIKARI
Class : 2nd year
Session : 2012-2013
Roll no. : 12
Date : 16.09.2012
Stone cladding is a thin layer of stone or simulated stone applied to a building or other
structure made of a material other than stone. Stone cladding is sometimes applied to
concrete and steel buildings as part of their original architectural design. Stone cladding
often refers to lightweight simulated stone products with a concrete type base. These
stone cladding products are often fitted to light weight substrates to reduce the material
cost of construction.
A lightweight substrate would typically be a timber stud frame, it would then have a
waterproof barrier attached, then fibre cement sheet, expanded metal mesh, a mortar
scratch coat, and then using a mortar mix, the stone cladding would be adhered to the
Stone cladding can also be a natural stone that has been quarried and then cut into thin
pieces to reduce weight. These heavier style stone cladding products often need
mechanical fixing to be adhered to substrates. Mechanical fixing could be using shelf
angles, or perhaps a product called stone clip.
stone cladding brings a feel of natural style and elegance to your home and the look is
unmatched by any other type of cladding. It uses thin layers of natural or simulated
stone. Stone cladding complements any surrounding. However, stone can be expensive
(simulated stone is somewhat cheaper than real stone however) and more labour
intensive than other types of cladding.
Types of Stone Used for Cladding
The principal rock types are granite, limestone, marble, sandstone, and slate although a
variety of igneous, metamorphic, and sedimentary rocks are also used.
Marble, Granite, Travertine, Limestone, Sandstone.
Concrete blocks, terrazo
Many surface finishes are possible with stone. The figure below show the graphic
symbols for typical stone finishes.
Stone Wall Patterns
Stone wall bond patterns can be roughly divide into two main groups.
• Manufactured stone is a simulated stone veneer made from lightweight concrete.
• It is colourfast, weather proof and has the look and feel of natural stone.
• Produced in a variety of colours and textures, it simulates various types of natural
Manufactured stone maybe applied directly to a base coat of stucco, concrete
block, brick, concrete or any masonry surface that has not been treated or sealed
and which is rough enough to provide a good mechanical bond.
• Manufactured stones are produced in different shapes and sizes to suit natural
stone wall patterns of rubble, and ashlar.
• The stones designed for ashlar bond pattern are available as either square or
rectangular slabs, which maybe fixed to the wall either:
a) in a simple square or rectangular grid pattern;
b) in a bond pattern
• Typical thickness of marble and slate slabs might be 18 mm, while lime stones and
sandstones tend to be thicker.
• Stone slabs are fixed back to the wall surface by many of non-ferrous metal
cramps (such as phosphor, bronze, brass or copper) as illustrated in the following
• One end of the cramp is built into the wall, while the other end hooks into a
recess in the slab. The cramps may be built into the wall by such means as either:
• setting the cramps into mortar joints as a brick wall,
• cutting a “pocket” (or mortise) in a concrete wall, and bedding the cramp into the
pocket with mortar.
• The manufactured stone can be cut with a brick trowel, hatchet or similar tool to
achieve sizes and shapes required for fitting stones and keeping mortar joints to a
Mortar used for manufactured stone should be a mixture of one part cement to
three parts clean sand.
To this is added from ¼ to ½ part lime, mortar cream or fire clay.
Packaged dry mix mortar that requires the addition of water also works well with
In any case mortar should be mix to a
consistency similar to that of brick
mortar. While the mortar is still soft and
pliable the stone should be pressed into
place with enough pressure so that the
mortar is squeezed out around the
edges of the stone. This will insure a
good bond between the stone and wall
When the mortar joints become firm
(from one to three hours depending on suction of the base and climate) they
should be pointed up with a wood and metal shrinking tool.
Excess mortar should be raked out and in the stone sealed around the edges to
give the finished job the appearance of a natural stone wall. At the end, the
finished wall should be broomed or wire brushed to remove loose mortar and to
clean the face of the stone.