STONE -As A Building Material. Stones have been considered as one of the popular building material from the olden days due to their availability in abundance from the natural rocks. Building stones should possess enough strength and durability. The stones which are suitable for the construction of the structures such as retaining walls, abutments, dams, barrages, roads etc are known as building stones.
WHAT IS STONE?
The hard, solid, non metallic mineral matter of which rock is made, a building material.
STONE -As A Building Material.
Stones have been considered as one of the popular building material from the olden days due to
their availability in abundance from the natural rocks. Building stones should possess enough
strength and durability.
The stones which are suitable for the construction of the structures such as retaining walls,
abutments, dams, barrages, roads etc are known as building stones.
SOURCES OF STONE
Monomineralic rock-monomineralic Applied to rocks composed of one mineral type only. Examples would
include the igneous rock anorthosite (composed entirely of plagioclase feldspar) and the metamorphic
rock marble (composed entirely of calcite).
Polymineralic rock-or “polymineralic,” i.e., mixtures of two or more minerals. An example of a polymineralic
rock is granite, which is typically composed of quartz, feldspar, and mica.
Rock forming minerals: ( Found in igneous rocks)
As a building material.
A)Igneous Rocks.-These are primary rocks which are formed from molten
magma. They represent different structural features depending upon the
condition of solidification and composition. Generally igneous rocks are strong
These are also called un stratified or eruptive rocks. The examples of igneous
rocks are granite, basalt, trap, etc.
b)Sedimentary rocks-These are secondary rocks and are formed by the denudation
and deposition of previously existing rocks due to weathering actions. Water (rain) is
the most powerful and principal weathering agent. The other destructive agents are
frost, winds and chemical actions. The destructive agents break up the surface of
earth which gets further broken up when carried down by rains and rivers. When the
velocity of water in the rivers those broken particles are deposited in the river bed and
thus sedimentary rocks are formed.
These are also called aqueous and stratified rocks.
The rocks which are formed by gradual deposition are called Sedimentary Rocks.
Examples: Lime stone, sand stone, etc.
Sandstones are made up of
sand sized grains
Limestones are the principal me
of carbonate rocks the limeston
is a light whitish-gray
c) Metamorphic rocks-Rocks which are formed due to metamorphic action of pressure
or internal heat or by both (or) alteration of original structure due to heat and excessive
pressure) are called Metamorphic Rocks.
Examples: Marble etc. New minerals are produced by this metamorphism. Shales
(mudstones) may be recrystallized into mica-rich rocks called schist. As such rocks are
heated to temperatures below but not far from those that would melt the rocks, they
become soft, recrystallize further, and can be deformed into crenulated light and dark
units that resemble layers, forming rocks called gneisses. Examples of slate, schist and
a)Stratified rocks-Stratified rocks show a layered structure in their natural environment.
They possess planes of stratification or cleavage and can be easily split up along
those planes. Sedimentary rocks are distinctly stratified rocks, eg; sandstone,
limestone, slate, etc.
b)Non stratified rocks-The rocks which do not show any sign of strata and cannot be
easily split into thin layers are called unstratified rocks. Their structure may be
crystalline or granular. Granite, trap and marble are the common examples of
c)Foliated rocks-There are two basic types of metamorphic rocks: 1) foliated
metamorphic rocks such as gneiss, phyllite, schist and slate which have a layered
or banded appearance that is produced by exposure to heat and directed pressure;
and, 2) non-foliated metamorphic rocks such as marble and quartzite which do not
have a layered ...
a)Siliceous rocks-The stones which contain (Silica SiO2) as principal constituent are
called silicious rocks. These stones are durable stones.
The examples of silicious rocks are granite, Quartzite and Sand stone etc.
b)Argillaceous rocks-Argillaceous or clay stones are those stones which contain
(alumina Al2O3) (clay) as principal constituent. These stones are less durable stones.
All clay stones belong to this group.
The examples of argillaceous rocks are Slate, Laterite, etc.
c)Calcareous rocks-The stones which contain calcareous material (CaCO3) as
principal constituent are called calcareous rocks. They also contain some proportion
of siliceous and clay matter.
The examples of calcareous rocks are marble stone and lime stone, etc.
Siliceous rocks Argillaceous Calcareous
Characteristics of Stones while considering them for construction
There are several characteristics of stones which are used for building
1)Hardness :denotes several qualities of stones such as resistance to cutting and resistance to abrasion
(rub with each other)
2) Durability: is the power of stone to resist atmospheric and other external effects.
It depends upon:
Chemical composition, Physical structure, Resistance to weathering effects, Place where it is
(3) Decomposition: Gases and acids in rain water dissolve
(4) Porosity and Absorption: Stone can hold water in two ways Either through porosity or
absorption.For building purposes, the better stones some constituents of stone and cause the
(5) Disintegration: In cold countries water freezes and expands and thus disintegrates the
(6)Reliability:When exposed to fire stone should be reliable (good in quality).
(7)Weight:This is an important characteristic of stone. It depends upon the type of structure of
stone in which we shall use. E.g. we shall use heavy stones in the construction of the dams,
(8)Strength:It is power of stone to sustain pressure or resistance to crushing force.
Average crushing strength of stone is 3 tons per square inch.
(8)Appearance and color:Highly colorful stones are preferred for architectural purpose but those
are soft and thus less durable. Therefore, lighter stones are preferred than to darker ones.
(9) Physical Strength:Crystalline structures are more durable than non-crystalline structure
(10)Seasoning Qualities:A good building stone should have good seasoning qualities. All the
stones contain some moisture which is known as quarry sap stones. The period 3-6 months are
enough for seasoning
(11)Fire resistance:A good building stone should be fire resistant. Some stones such as basalt
Uses Of Stone in Construction
Common Uses Of Builiding Stones:
1.Millions of tones of crushed rock are needed annually for road base,
paving, 2.ready-mixed concrete and asphalt.
3.Sandstone which is not so hard-wearing or beautifully patterned is used
for 4.garden walls and paths in landscaping.
5.Basalt: It is quarried and crushed as "Blue Metal" which is used as a
road-base, and in reinforced concrete as aggregate.
6.Although wood, straw and mud is used for houses in some parts of the
world, most buildings are preferred to be built of stones.
8.Material for foundation and walling of buildings, dams, bridges, etc.
11.Roof tile in the form of slates.
12.Murram for covering and flooring of road surface.
13.Limestone for burning lime and for the manufacture of Portland
14.Shale is a component of bricks and may also be used in
manufacturing of cement.
15.Nite, another stone type is used for architectural construction,
ornamental stones and monuments.
16.Marble is widely used in construction industry, for aesthetic purposes,
What is stone masonry?
The construction of stones bonded together with mortar is termed as stone masonry
where the stones are available in a abundance in nature, on cutting and dressing to the
proper shape, they provide an economical material for the construction of various
building components such as walls, columns, footings, arches, lintels, beams etc.
Where is stone masonry used?
Dams, light houses, monumental structures.
Railway, ballast, black boards and electrical switch boards
Building foundations, walls, piers, pillars, and architectural works.
Lintels, Beams, beams Arches, domes etc.
Roofs and Roof coverings.
What are the criteria's of selecting A building stone?
2.Strength and stability
4.Ease of working
Stone Masonry-General Principals For Laying Stone Masonry.
1.The stones to be used for stone masonry should be hard, tough and durable.
2.The pressure acting on stones should be vertical.
3.The stones should be perfectly dressed as per the requirements.
4.The heads and bond stones should not be of a dumb bell shape.
5.n order to obtain uniform distribution of load, under the ends of girders,
roof trusses etc large flat stones should be used.
6.The mortar to be used should be good quality and in the specified faces.
7.The construction work of stone masonry should be raised uniformly.
8. The plumb bob should be used to check the verticality of erected wall.
9.The stone masonry section should always be designed to take
compression and not the tensile stresses.
10.The masonry work should be properly cured after the completion of work,
for a period of 2 to 3 weeks.
11.As far as possible broken stones or small stones chips should not be used.
12.Double scaffolding should be used for working at higher level.
13.The masonry hearting should be properly packed with mortar and chips if
necessary to avoid hallows.
14.The properly wetted stones should be used to avoid mortar moisture being
Laying The Stone
1.Decrease the stone thickness from the bottom to the top of wall.
2. Ensure that the headers in the heart of the wall are the same size as in the face
and extend at least 12 in (300 mm) into the core or back. (Avoid Dumb-bell
3.Ensure that headers in “walls of 2 feet (600 mm) or less in thickness” extend
entirely through the wall. The headers shall occupy at least 20 percent of the face
of the wall.
4. Lay the masonry in roughly leveled courses. Ensure that the bottom of the
foundation is large, with selected stones.
5. Lay the courses with leaning beds parallel to the natural bed of the material.
6. Regularly diminish the thicknesses of the courses, if varied, from the bottom to
the top of the wall. Keep a surplus supply of stones at the site to select from.
7. Before laying the stone in the wall, shape and dress it so that it will not loosen
after it is placed. No dressing or hammering which will loosen the stone will be
permitted after it is placed.
8. Clean each stone and saturate it with water before setting it. Clean and moisten
the bed that will receive it.
9.Bed the stones in freshly made mortar with full joints. Carefully settle the stones
in place before the mortar sets.
10. Ensure that the joints and beds have an average thickness of not more than 1
inch. (25 mm).
11. Do not place vertical joints directly above or below a header joint.
12.If a stone is moved or if the joint is broken after the mortar has set, take the
stone up and thoroughly clean the mortar from the bed and joints. Reset the
stone in fresh mortar.
13. Note: Do not lay the masonry in freezing weather or when the stone
contains frost, except with permission subjected to the required conditions.
14.Whenever possible, properly point the face joints before the mortar sets. If
joints cannot be pointed, rake them out to a depth of 1 in (25 mm) before the
15.Do not smear the stone face surfaces with the mortar forced out of the
joints or the mortar used in pointing.
16.Thoroughly wet the joints pointed after the stone is laid with clean water
and fill with mortar.
17. Drive the mortar into the joints and finish with an approved pointing tool.
18. Keep the wall wet while pointing. In hot or dry weather, protect the pointed
masonry from the sun and keep it wet for at least three days after the pointing
19. Note: Do not perform pointing in freezing weather or when the stone
20. After the pointing is completed and the mortar is set, thoroughly clean the
walls and leave them in a neat condition
MASONRY: Construction of building units bonded together, Masonry is basically a
wall material. Masonry walls are divided into three categories, they are
1. Load bearing walls
2. Non-load bearing walls
3. Retaining walls
STONE MASONRY: From times immemorial, stone has been used both for
residential as well as public buildings. Historical buildings that stand today are the
living examples of the strength, durability and the excellent weather resisting
qualities of stone masonry.
Because of high crushing strength, stone is used in the construction of piers, docks,
dams and other marine structures.
But dressing and placing of stone requires a great deal of time and extra labour.
Depending upon the degree of refinement used in shaping the stone, the finishing
adopted and the arrangement of the stone in the construction, stone masonry can be
broadly classified in the following two types:
1. Rubble masonry
2. Ashlar masonry
Rubble Masonry: It is further sub-divided in the following categories
1. Uncoursed rubble masonry
2. Random rubble masonry
3. Coursed rubble masonry
4. Dry rubble masonry . Definitions of terms:
Definitions of terms:
Course: A course is a horizontal layer of bricks stones
Bed: the surface of a stone perpendicular to the line of pressure of (lower surface of
bricks or stones in each course)
Back: The inner surface of wall not exposed is called back. The material forming back
is known as backing
Face: The exterior of the wall exposed to weather is known as face. The material
used in the facing of wall is known as facing’
Hearting: It is the interior portion of a wall between facing and backing
Head: It is a brick or stone, which lies with its greatest length at right angles to the
face of the work.
Stretcher: It is a brick or a stone which lies with its congest side parallel to the face of
Bond: The method of arranging bricks so that the individual units are tied together
Spalls: The chips of stones used for filling the interstics in stone masonry
Quoins: The stones used for the corners of walls of structure
Bat: It is a portion of a brick cut across the width.
Closer: It is the portion of a brickcut in such a manner that its one long face remains
Queen closer: it is the portion of a brick obtained by cutting a brick length-
wise into two portions
King closer: It is the portion of brick obtained by cutting off the triangular
piece between the centre of one end and the centre of one side.
Bevelled closer: It is the portion of a brick in which the whole length of the
brick is bevelled for maintaining half width at one end and full width at the
Frog: It is an indentation or depression on the top face of a brick made with
the object of forming a key for the mortar.
Sill: It is a horizontal stone, concrete or wood, employed for the purpose of
shedding off rain water from the face of wall immediately below the window
Corbel: It is the extension of one or more course of stone or brick from the
face of a wall to serve as a support for wall plates
Templates: Pieces of stones placed under the end of a beam to distribute
load over a greater area.
Coping: It is the course placed upon the exposed top of an external wall to
prevent the seepage of water
Buttress: It is a sloping or stepped masonry projection from a tall wall
intended to strengthen the wall against the thrust of a roof as shown in figure.
Uncoursed Rubble Masonry: This is the poorest form of stone masonry. The
stones to be used are directly obtained from quarry, after merely knocking off
weak corner and edges With the masons hammer. The Face stones selected
from the heap should have uniform colour, uniform bed and greater size. In this
type the stone blocks are made roughly square with hammer. Generally the
facing stones are given hammer-dressed finish. Large stones are used as
quoins. As far as possible the use of chips in bedding is avoided.
Random Squqre Rubble masonry
This form is slightly superior to uncoursed rubble masonry in this form the stones
used in the work are hammer or chisel dressed. The stone are not suitably shaped
or finished and as such the elevation of this type masonry show irregular shape
stones with non uniform joints. In good work the face stones are of uniform colour
In this type of stone masonry the uniform height stones are used in horizontal
layers not less than 13cm in height. Generally, the stone beds are hammered
or chisel dressed to a depth of at least 10cm from the face. The stones are
arranged in such a manner so that the vertical joints of two consecutive curse do
not coincide with each other as shown in figure below
Coursed Rubble Masonry: This is the form of masonry which is commonly
adopted in residential building, public building, piers and abutments for
ordinary bridges. Considering the dressing and finishing of stones it is further
subdivided into 1st class, 2nd class and 3rd class. In first class masonry,
generally all the courses are of the same height and the minimum height of the
course is limited to 15 cm. The face stones are hammer dressed. The beds of
the face stone or hammer or chisel dressed and rendered true and square.
In this type of stone masonry the uniform height stones are used in
horizontal layers not less than 13cm in height. Generally, the stone beds
are hammered or chisel dressed to a depth of at least 10cm from the face.
The stones are arranged in such a manner so that the vertical joints of two
consecutive curse do not coincide with each other as shown in figure below
(v) Polygonal rubble masonry: In this type of masonry the stones are roughly dressed
to an irregular polygonal shape. The stones should be so arranged as to avoid long
vertical joints in face work and to break joints as much as possible. Small stone chips
should not be used to support the stones on the facing as shown in the figure below.
Dry Rubble Masonry: The construction of this form is similar to that of ordinary rubble
masonry without mortar.
Flint Rubble Masonry
(vi) Flint rubble masonry: This type of masonry is used in the areas where the flint is
available in plenty.
The flint stones varying in thickness from 8 to 15cm and in length from 15 to 30cm
are arranged in the facing in the form of coursed or uncoursed masonry as shown
Ashlar Masonry: The work built from carefully dressed stones with accurate
bedding and jointing is termed as ashlars masonry. This construction is further
subdivided into various types they are
1. Ashlar fine
2. Ashlar rough tool
3. Ashlar chamfered
4. Ashlar facing
Ashlar Fine: In this type of masonry, all the stones are fine tooled; all bed and side
joint faces are rendered perfectly true to pattern desired.
The height of the courses is never less than 30 cm. The bed and the side joint in
this type of work should never exceed 3mm in thickness.
Dry rubble masonry
This type of masonry is used in
the construction of retaining
walls pitching earthen dams and
canal slopes in the form of
random rubble masonry without
any mortar. The hallow spaces
left around and stones should be
tightly packed with smaller stone
pieces as shown below.
Ashlar Rough Tool: In this type of masonry the exposed faces of stone generally have
a fine dressed chisel drafting all round the edges. The portion the face stone enclosed
by the chisel draft is rough tooled. The thickness should never exceed 6mm.
Ashlar Champhered : This type masonry is similar to the one described above with the
only difference that the edges around the exposed faces of stone are bevelled off at an
angle of 45O for depth of 25mm or more
Ashlar Facing: In this type of masonry the faces of stone are rough tooled, and
chamfered and the stones are provided in face work only. The backing may be made
in brick, concrete, or rubble as desired. The composite construction reduces the cost
of work appreciably the height of the course is never kept less than 20cm.
Selection Of Stone Masonry
Recommended Use of Common Types of Stone
S. No Situation Types of Stones Used
1. For face work of building. Marble, granite and
close-grained sand. Stone.
2. For curved or ornamental works. Soft sand stone and
3. For masonry work in industrial town Granite, compact
sandstone and Exposed to smoke and chemical fumes.
4. For road metal. Basalt and coarse-grained
5. For railway ballast. Sand stone, granite and
6. For paving’s, door sills and steps. Marble, slates and sand
7. For bridges, piers, docks
8. For fire resistant masonry Compact sand stone.
Dressing Of Stones
Building stones has to quarried out from the rock formation before it can be put into
use quarry of the stone may be done either by hand tool or with the help explosives. In
large quarries, a machine has to be used for the purpose. Rough block of stone are
obtained from quarry are irregular in shape and non uniform in size and as such they
cannot be used in without proper dressing and cutting. 8
The commonly used tools and implements for the cutting and dressing of stone blocks
2. Face hammer
3. Scabbling hammer
6. Mash hammer
7. Spalling hammer
8. Pitching tool
11. Toothed chisel
12. Claw chisel
15. Saw for soft stone
16. Crosscut saw
(1).Hammer Dressed or Quarry Faced
This is the roughest form of surface finish. Stone as removed from the quarry has
large projections which are knocked off with the quarry hammer and it is finally
broken up into blocks of suitable size and shape such as khandi, quoin, or
(2). Rough Tooled Surface.
In this type of surface finish, the projection of the stone block is removed by means
of chisels and the surface is nearly dressed true.
(3). Tooled Surface
In this type of surface finish continuous parallel chisel marks are produced
throughout the width of the stone. The parallel corrugations or chisel marks are
made at closer intervals rendering the surface truly planned.
(4). Cut Stone Surface
In this type of surface finish the surface is dressed by using a sharp chisel so that
the chisel marks are practically imperceptible.
(5). Rubbed Surface
This type of surface finish is obtained by grinding or rubbing a cut stone surface by
hand or machine until it gets perfectly smooth
(6). Polished Surface
The Rubbed surfaces of granite, marble of lime stones are polished to enhance their
texture. Polishing may be done by manual labour using sand and water, pumice
stone etc. Or by rubbing machine