Tuesday, October 13, 2020

Falling Water


The house was built partly over a waterfall on Bear Run in the Mill Run section of Stewart Township, Fayette County, Pennsylvania, located in the Laurel Highlands of the Allegheny Mountains. The house was designed as a weekend home for the family of Liliane Kaufmann and her husband, Edgar J. Kaufmann Sr., owner of Kaufmann's Department Store.

Architect : 

Frank Lloyd Wright (June 8, 1867 – April 9, 1959) He was an American architect, interior designer, writer, and educator, whose creative period spanned more than 70 years, designing more than 1,000 structures, of which 532 were completed. Wright believed in designing structures that were in harmony with humanity and its environment, a philosophy he called organic architecture. This philosophy was best exemplified by Fallingwater (1935), which has been called "the best all-time work of American architecture." As a founder of organic architecture, Wright played a key role in the architectural movements of the twentieth century, influencing three generations of architects worldwide through his works.

Location : rural southwestern Pennsylvania, 43 miles (69 km) southeast of Pittsburgh.

Architectural style : Modern Architecture

Construction started : 1936

Construction completed : 1939

Functions : 

Fallingwater was the family's weekend home from 1937 until 1963, when Edgar Kaufmann Jr. donated the property to the Western Pennsylvania Conservancy. The family retreated at Fallingwater on weekends to escape the heat and smoke of industrial Pittsburgh. Liliane enjoyed swimming in the nude and collecting modern art, especially the works of Diego Rivera, who was a guest at the country house.

Building elements : 

Fallingwater was designed in two parts: the main house (5,330 sq.ft) and the guest house (1,700 sq.ft). It is centre around the fireplace, cut into by a rock which brings the waterfall physically inside. The natural surroundings incorporated throughout the house, such as the living room which includes steps that lead directly to the water below.

The house includes :

First floor: Open living room, compact kitchen, and simple rooms.

Second floor: Three small bedrooms.

Third floor: Study and bedroom.

Dark and narrow passageways were designed to give a sense of compression that contrast in dramatic  style with the sense of expansion in the larger rooms. Wright designed the ceilings to be relatively low – only 6'4” in some places, to direct the eye to the outside. Externally, the chimney is extended upwards to make it the highest point on the house. Long cantilevered terraces made of reinforced concrete protrude in a series of right angles to add an element of sculpture as well as a strong horizontal emphasis. Wright allowed nature to determine the building's elements, including a trellis beam, bent to accommodate a pre-existing tree. The house uses a large amount of glass, with no exterior wall facing the waterfalls. Instead there is only a central stone core for the fireplaces and stone columns. Wright used 'corner-turning windows' without mullions to 'break the box of the house and cause the corners to vanish'. Despite suggesting that the house's concrete surfaces be coated in gold leaf, Wright only used two colours throughout the house – a light ochre for the concrete and a Cherokee red for the steel. This limited colour palette created a unified and organic composition.

Saturday, September 19, 2020

Burj Khalifa

The Burj Khalifa, known as the Burj Dubai , is a skyscraper in Dubai, United Arab Emirates. With a total height of 829.8 m and a roof height of 828 m. The Burj Khalifa has been the tallest structure and building in the world since its topping out in 2009. 

Owner :  Emaar Properties

Architect : Adrian D. Smith 

Architectural style : Neo-futurism

Located at : Dubai

Construction started : 6th January,2004

Construction completed : 1st October,2009


1.The Dubai Fountain

 Outside, WET Enterprises designed a fountain system at a cost of 800 million. Illuminated by 6,600 lights and 50 coloured projectors, it is 270 m (900 ft) long and shoots water 150 m (500 ft) into the air, accompanied by a range of classical to contemporary Arabic and other music. It is the world's second largest choreographed fountain. On 26 October 2008, Emaar announced that based on results of a naming contest the fountain would be called the Dubai Fountain.

2.Observation deck

An outdoor observation deck, named At the Top, opened on 5 January 2010 on the 124th floor. At 452 m, it was the highest outdoor observation deck in the world when it opened. Although it was surpassed in December 2011 by Cloud Top 488 on the Canton Tower, Guangzhou at 488 m, Burj Khalifa opened the 148th floor SKY level at 555 m, once again giving it the highest observation deck in the world on 15 October 2014, until the Shanghai Tower opened in June 2016 with an observation deck at a height of 561 metres.

3.Burj Khalifa park

Burj Khalifa is surrounded by an 27-acre park designed by landscape architects SWA Group. Like the tower, the park's design was based on the flower of the Hymenocallis, a desert plant. At the centre of the park is the water room, which is a series of pools and water jet fountains. Benches and signs incorporate images of Burj Khalifa and the Hymenocallis flower. The plants are watered by water collected from the building's cooling system. The system provides 68,000,000 L annually. WET Enterprises, who also developed the Dubai Fountain, developed the park's six water features.

Construction Highlights :
Over 45,000 m3 of concrete, weighing more than 110,000 tonnes were used to construct the concrete and steel foundation, which features 192 piles buried more than 50 m (164 ft) deep. Burj Khalifa's construction will have used 330,000 m3 of concrete and 39,000 tonnes of steel rebar, and construction will have taken 22 million man-hours. 
The exterior cladding of Burj Khalifa began in May 2007 and was completed in September 2009. The vast project involved more than 380 skilled engineers and on-site technicians. At the initial stage of installation, the team progressed at the rate of about 20 to 30 panels per day and eventually achieved as many as 175 panels per day. The tower accomplished a world record for the highest installation of an aluminium and glass fa├žade with a height of 512 metres. 
The total weight of aluminium used on Burj Khalifa is equivalent to that of five A380 aircrafts and the total length of stainless steel bull nose fins is 293 times the height of Eiffel Tower Paris. In November 2007, the highest reinforced concrete core walls were pumped using 80 MPa concrete from ground level. A vertical height of 601 metres. 
This smashed the previous pumping record on a building of 470m on Taipei 101; the world’s second tallest tower and the previous world record for vertical pumping of 532 metres for an extension to the Riva del Garda Hydroelectric Power Plant in 1994. The concrete pressure during pumping to this level was nearly 200 bars. The amount of rebar used for the tower is 31,400 metric tons laid end to end this would extend over a quarter of the way around the world.

Burj Khalifa Construction Timeline:

  January 2004 : Excavation started
        February 2004 : Piling started
March 2005 : Superstructure started
June 2006 : Level 50 reached
  January 2007 : Level 100 reached
  March 2007 : Level 110 reached
  April 2007 : Level 120 reached
  May 2007 : Level 130 reached
  July 2007 : Level 141 reached (world's tallest building)
  September 2007 : Level 150 reached (world's tallest free-standing  structure)
  April 2008 : Level 160 reached ( world's tallest man-made  structure)
  January 2009 : Completion of spire (Burj Khalifa tops out)
  September 2009 : Exterior cladding completed
  January 2010 : Official launch ceremony

Friday, September 11, 2020



Introduction :

Wood is a hard and fibrous substance which forms a major part of the trunk and branches of a tree. It can also be defined as a natural polymeric material which practically does not age. Wood as a building material falls in two major classes i,e, natural and man-made. With the advances in science and technology, wood in its natural form as timber, lumber, etc. is being rapidly replaced by composite wood materials in which natural wood is just a basic ingredient of a matrix or a laminate. The latter are found to be more useful and adaptable as they may be treated chemically, thermally or otherwise as per requirements. Some examples are plywood, fibreboards, chipboards, compressed wood, impregnated wood, etc.

Wood is a good absorber of shocks and so is suitable for construction work in hilly areas which are more prone to earthquakes. Finally, since wood can be easily worked, repairs and alterations to wood work can also be done easily. Owing to the above mentioned advantages, wood is very widely used in buildings as doors, windows, frames, temporary partition walls, etc. and in roof trusses and ceilings apart from formwork. 

Market Forms of Timber :

Battens: Timber pieces whose breadth and thickness do not exceed 50 mm. 

Baulk: Roughly squared timber piece, it is obtained by removing bark and Sapwood. One cross sectional dimension exceeds 50 mm, while the other exceeds 200mm. 

Board: A plank with parallel sides. Its thickness is less than 50mm and width exceeds 150mm. 

Deal: Piece of soft wood with parallel sides. Thickness varies from 50mm to 100mm and width does not exceed 230mm. 

Log: Trunk of tree obtained after removal of branches. 

Plank: Timber pieces with parallel sides. Thickness less than 50mm and width exceeds 50mm. 

Pole: Sound long log of wood, dia does not exceed 200mm, also known as spar.

Quartering: Square piece of timber, the length of side being 50mm to 150mm. 

Scantling: Timber piece whose breadth and thickness exceed 50mm,but are less than 200mm in length. These are the pieces of misc sizes of timber sawn out of a log. 

Types of engineered wood available in market:
c)Fibre boards
d)Particle boards
f)Batten and Lamine boards

A wood panel glued under pressure from an odd number (usually 3 to 13) of layers/piles of veneers is known as plywood. The outer most veneer sheets in a plywood panel are called faces. The interior ply which have their grain directions parallel to that of the faces are termed as core or centre. Other piles which have grain directions perpendicular to that in the face are termed as cross bands.
Plywood may be classified upon direction of grains in the plies and on the type of adhesive used. Normally the alternate plies are oriented at 30° or 60° in star plywood. The faces are arranged with the grain at 45° to that of the centres in diagonal plywood. When the plies are bonded together with water-soluble glues such as casein glue, interior grade plywood is obtained and when bonded with phenol formaldehyde adhesive it is identified as exterior grade plywood which is completely water proof. 

Sizes available :
2400 x 1200 mm
2100 x 1200 mm
1800 x 1200 mm
2400 x 900 mm
2100 x 900 mm
1800 x 900 mm
Thickness vary from 3mm to 25mm.
Applications : Used for partitions, ceiling, door, concrete form work, etc.

b)Veneers :
The primary process in the manufacture of wood based products is veneering which produces thin sheets of wood known as veneers. The thickness of veneers varies from 0.4 to 0.6 mm. In no case it should exceed 1 mm. The most suitable wood for this purpose is walnut. However other species like teak, sissoo, rose wood, etc. are also used. The logs to be used for this purpose are kept in wet storage to avoid end splitting and are softened by heating with hot water or steam and the bark is removed. The log is then cut to veneers. Depending on the cutting process, the veneers are classified as rotary veneers and sliced veneers. These are used in the manufacture of plywood and other laminated boards.  

Sizes available:
i)Thickness vary from 0.4 to o.6 mm.
ii)In no case it should exceed 1 mm.
Applications : Used for doors, tops and side panels for cabinet, wooden flooring, etc.

c)Fibre boards:
These boards built up of felting from wood or vegetable (wood wastes, waste paper, agricultural wastes, etc.) are classified by the process of their moulding. If the boards are moulded by wet process, the main bond is by the felting of woody fibres and not by added glue. For the boards moulded by dry process, the bond between the predried fibres is improved by adding 4–8% of synthetic resin. For better performance wood preservatives and other admixtures are often added to the pulp. Insulating boards are not compressed during manufacture. Fibre boards are manufactured in various densities like soft, medium and hard. The soft boards are used for walls and ceilings. Medium boards find their application in panelling, partition walls, doors and windows. Hard boards have one surface smooth and the other one textured. These have higher densities, better mechanical properties, and improved moisture and termite resistances. The strength and weather properties of hard boards can be improved by oil tempertering and such boards are known as tempered hard boards. Some of the trade names of hard boards are Masonite, Celotex, Essex boards, etc.

Applications : Widely used for walls, ceiling, cladding, partitions, doors, perforated acoustic tiles, bus bodies, etc.

d)Particle boards :
They are manufactured from particles of wood or other ligno cellulose materials which are agglomerated, formed and pressed together by the use of an organic binder together in the presence of heat, pressure or moisture. They are manufactured from small timber pieces and wood wastes. The latter is first converted into small chips. The moisture content of chips is reduced to a certain percentage and then some gluing material, usually phenol formaldehyde, is sprayed. The chips are then spread to form a mat and then pressed in a hydraulic press in presence of heat and moisture. Particle boards avoid wastage of timber as in its making the entire volume of the fallen tree can be utilized. The trees used for making particle boards are eucalyptus, subabool, and rubber wood, and waste of saw mill. These boards provide dimensional stability, smooth uniform surface, and no difficulty in nailing.

Sizes available:
Sizes vary from 4ft to 8ft panels.
Applications : Widely used in buildings, ceilings, floor slabs, door, furniture, etc.

e)Block board :
The core of block boards is made up of strips of wood each not exceeding 25 mm in width, forming a slab, glued between at least two surface veneers. Veneers used for cross bands and faces are either rotary cut or sliced and should be reasonably smooth. Cross band thickness varies between 1–3 mm and face veneers between 0.5 to 1.5 mm in thicknesses. The directions of the grains of the core blocks run at right angles to that of the adjacent outer veneers. 

Sizes Available :
These are available in thicknesses of 12, 15, 19, 25, 30, 35, 40 and 50 mm. 
Block Boards are available in sizes - 
2400 × 1200 mm
2100 × 1200 mm
1200 × 900 mm
1800 × 1200 mm
1800 × 900 mm 
Applications : These are extensively used for construction of railways carriages, bodies of buses, marine and river crafts, partitions, furniture, etc. 

f)Batten and Lamine boards :
Batten boards have core made up of 80 mm wide wood pieces, forming a slab glued between at least two surface veneers. Whereas, Lamin boards have a core of strips, each not exceeding 7 mm in thickness, glued together to form a slab which in turn is glued between two or more outer veneers. The directions of the grains of the core block run at right angles to that of the adjacent outer veneers.

Wednesday, September 9, 2020



                                                                  VITRUVIAN MAN

       Anthropometry refers to the measurement of the size and proportions of the human body. While the architects of the Renaissance saw the proportions of the human figure as a reaffirmation that certain mathematical ratios reflected the harmony of their universe, anthropometric proportioning methods seek not abstract or symbolic ratios, but functional ones. They are predicated on the theory that forms and spaces in architecture are either containers or extensions of the human body and should therefore be determined by its dimensions. The difficulty with anthropometric proportioning is the nature of the data required for its use. For example, the dimensions given here in millimeters are average measurements and are merely guidelines that should be modified to satisfy specific user needs. Average dimensions must always be treated with caution since variations from the norm will always exist due to the difference between men and women, among various age and racial groups, even from one individual to the next.

      The dimensions and proportions of the human body affect the proportion of things we handle, the height and distance of things we try to reach, and the dimensions of the furnishings we use for sitting, working, eating, and sleeping. There is a difference between our structural dimensions and those dimensional requirements that result from how we reach for something on a shelf, sit down at a table, walk down a set of stairs, or interact with other people. These are functional dimensions and will vary according to the nature of the activity engaged in and the social situation. A special field that has developed from a concern with human factors is ergonomics the applied science that coordinates the design of devices, systems, and environments with our physiological and psychological capacities and requirements. In addition to the elements that we use in a building, the dimensions of the human body also affect the volume of space we require for movement, activity, and rest. The fit between the form and dimensions of a space and our own body dimensions can be a static one as when we sit in a chair, lean against a railing, or nestle within an alcove space. There can also be a dynamic fit as when we enter a building’s foyer, walk up a stairway, or move through the rooms and halls of a building. A third type of fit is how a space accommodates our need to maintain appropriate social distances and to have control over our personal space.

Scale :

     While proportion pertains to an ordered set of mathematical relationships among the dimensions of a form or space, scale refers to how we perceive or judge the size of something in relation to something else. In dealing with the issue of scale, therefore, we are always comparing one thing to another. The entity an object or space is being compared to may be an accepted unit or standard of measurement. For example, we can say that a table is, according to the U.S. Customary System, 3 feet wide, 6 feet long, and 29 inches high. Using the International Metric System, the same table would measure 914 mm wide, 1829 mm long, and 737 mm high. The physical dimensions of the table have not changed, just the system used to calculate its size. In drawing, we use a scale to specify the ratio that determines the relationship between an illustration to that which it represents. For example, the scale of an architectural drawing notes the size of a depicted building in comparison to the real thing.

Visual Scale :
       Of particular interest to designers is the notion of visual scale, which refers not to the actual dimensions of things, but rather to how small or large something appears to be in relation to its normal size or to the size of other things in its context. When we say something is small-scale or miniature, we usually mean that thing appears to be smaller than its usual size. Likewise, something that is large-scale is perceived as being larger than what is normal or expected. We speak of urban scale when we refer to the size of a project in the context of a city, or neighborhood scale when we judge a building appropriate to its locale within a city, or street scale when we note the relative sizes of elements fronting a roadway. At the scale of a building, all elements, no matter how plain or unimportant they may be, have a certain size. Its dimensions may be predetermined by the manufacturer, or they may be selected by the designer from a range of choices. Nevertheless, we perceive the size of each element in relation to other parts or to the whole of a composition. For example, the size and proportion of windows in a building facade are visually related to one another as well as to the spaces between them and the overall dimensions of the facade. If the windows are all of the same size and shape, they establish a scale relative to the size of the facade. If, however, one of the windows is larger than the others, it would create another scale within the composition of the facade. The jump in scale could indicate the size or significance of the space behind the window, or it could alter our perception of the size of the other windows or the overall dimensions of the facade.

Human Scale :
        Human scale in architecture is based on the dimensions and proportions of the human body. It has already been mentioned in the section on anthropometric proportioning that our dimensions vary from individual to individual and should not be used as an absolute measuring device. We can, however, gauge a space whose width is such that we can reach out and touch its walls. Similarly, we can judge its height if we can reach up and touch the ceiling plane overhead. Once we can no longer do these things, we must rely on visual rather than tactile clues to give us a sense of the scale of a space. For these clues, we can use elements that have human meaning and whose dimensions are related to the dimensions of our posture, pace, reach, or grasp. Such elements as a table or chair, the risers and treads of a stairway, the sill of a window, and the lintel over a doorway, not only help us judge the size of a space but also give it a human scale.

A Scaler Comparison :
      On these the architectural structures from various historic periods and places drawn to the same or similar scale. Our perception of how big something or someplace is always relative to its context and to the size of what we are familar with, such as the length of a Boeing 747 airliner.

FRANCIS D.K. CHING (Form Space Order)

Friday, September 4, 2020



What is circulation?????

The path of our movement can be conceived as the perceptual thread that links the spaces of a building, or any series of interior or exterior spaces, together. Since we move in Time through a Sequence of Spaces we experience a space in relation to where we’ve been and where we anticipate going. This artical presents building’s circulation system as positive elements that affect our perception of the forms and spaces of the building.

Main circulation elements :

1) Approach (The Distant View) :
Prior to actually passing into the interior of a building, we approach its entrance along a path. This is the first phase of the circulation system, during which we are prepared to see, experience, and use the spaces within a building.
The approach to a building and its entrance may vary in duration from a few paces through a compressed space to a lengthy and circuitous route. It may be perpendicular to the primary facade of a building or be oblique to it. The nature of the approach may contrast with what is confronted at its termination, or it may be continued on into the building’s interior sequence of spaces, obscuring the distinction between inside and outside.
a) Frontal:
A frontal approach leads directly to the entrance of a building along a straight, axial path. The visual goal that terminates the approach is clear; it may be the entire front facade of a building or an elaborated entrance within the plane.
b) Oblique:
An oblique approach enhances the effect of perspective on the front facade and form of a building. The path can be redirected one or more times to delay and prolong the sequence of the approach. If a building is approached at an extreme angle, its entrance can project beyond its facade to be more clearly visible.
c) Spiral:
A spiral path prolongs the sequence of the approach and emphasizes the three-dimensional form of a building as we move around its perimeter. 
The building entrance might be viewed intermittently during the approach to clarify its position or it may be hidden until the point of arrival.

2) Entrance (From Outside to Inside) :
   Entering a building, a room within a building, or a defined field of exterior space, involves the act of penetrating a vertical plane that distinguishes one space from another and,
separates ”here” from “there.” The act of entering can be signified in more subtle ways than punching a hole in a wall. It may be a passage through an implied plane established by two pillars or an overhead beam. In situations where greater visual and spatial continuity between two spaces is desired, even a change in level can establish a threshold and,
mark the passage from one place to another. In the normal situation where a wall is used to define and enclose a space or series of spaces, an entrance is accommodated by an opening in the plane of the wall. The form of the opening, however, can range from a simple hole in the wall to an elaborate, articulated gateway.
*The notion of an entrance can be visually reinforced by:
• making the opening lower, wider, or narrower than anticipated
• making the entrance deep or circuitous
• articulating the opening with ornamentation or decorative embellishment

3) Configuration of the Path (The Sequence of Spaces) :
All paths of movement, whether of people, cars, goods, or services, are linear in nature. And all paths have a starting point, from which we are taken through a sequence of spaces to our destination. The contour of a path depends on our mode of transportation. While we as pedestrians can turn, pause, stop, and rest at will, a bicycle has less freedom, and a car even less, in changing its pace and direction abruptly. Interestingly though, while a wheeled vehicle may require a path with smooth contours that reflect its turning radius, the width of the path can be tailored tightly to its dimensions. Pedestrians, on the other hand, although
able to tolerate abrupt changes in direction, require a greater volume of space than their bodily dimensions and greater freedom of choice along a path.
The nature of the configuration of a path both influences and is influenced by the organizational pattern of the spaces it links. The configuration of a path may reinforce a spatial organization by paralleling its pattern. Or the configuration may contrast with the form of the spatial organization and serve as a visual counterpoint to it. Once we are able to map out in our minds the overall configuration of the paths in a building, our orientation within the building and our understanding of its spatial layout will be made clear.
a) Linear
All paths are linear. A straight path, however, can be the primary organizing element for a series of spaces. In addition, it can be curvilinear or segmented, intersect other paths, have branches, or form a loop.
b) Radial
A radial configuration has linear paths extending from or terminating at a central, common point.
c) Spiral
A spiral configuration is a single, continuous path that originates from a central point, revolves around it, and becomes increasingly distant from it.
d) Grid
A grid configuration consists of two sets of parallel paths that intersect at regular intervals and create square or rectangular fields of space.
e) Network
A network configuration consists of paths that connect established points in space
f) Composite
In reality, a building normally employs a combination of the preceding patterns. Important points in any pattern are centers of activity, entrances to rooms and halls, and places for vertical circulation provided by stairways, ramps, and elevators.

4) Path-space Relationships (Edges, Nodes, and Terminations of the Path) :
Paths may be related to the spaces they link in the following ways. They may :
a) Pass by Spaces:
• The integrity of each space is maintained.
• The configuration of the path is flexible.
• Mediating spaces can be used to link the path with the spaces.
b) Pass through Spaces:
• The path may pass though a space axially, obliquely, or along its edge.
• In cutting through a space, the path creates patterns of rest and movement within it
c) Terminate in a Space:
• The location of the space establishes the path.
• This path-space relationship is used to approach and enter functionally or symbolically important spaces.

5) Form of the Circulation Space (Corridors, Halls, Galleries, Stairways and Rooms) :
Spaces for movement form an integral part of any building organization and occupy a significant amount of the volume of a building. If considered merely as functional linking devices, then circulation paths would be endless, corridor-like spaces. The form and scale of a circulation space, however, should accommodate the movement of people as they promenade, pause, rest, or take in a view along a path.
The form of a circulation space varies according to how :
• its boundaries are defined;
• its form relates to the form of the spaces it links;
• its qualities of scale, proportion, light, and view are articulated;
• entrances open onto it; and
• it handles changes in level with stairs and ramps.
A circulation space may be:
a) Enclosed
Forming a public galleria or private corridor that relates to the spaces it links though entrances in a wall plane;
b) Open on One Side
Forming a balcony or gallery that provides visual and spatial continuity with the spaces it links.
c) Open on Both Sides
Forming a colonnaded passageway that becomes a physical extension of the space it passes through. The width and height of a circulation space should be proportionate with the type and amount of movement it must handle. A distinction in scale should be established between a public promenade, a more private hall, and a service corridor.


Tuesday, September 1, 2020



       The roof system functions as the primary sheltering element for the interior spaces of a building. The form and slope of a roof must be compatible with the type of roofing shingles, tiles, or a continuous membrane used to shed rainwater and melting snow to a system of drains, gutters, and downspouts. The construction of a roof should also control the passage of moisture vapor, the infiltration of air, and the flow of heat and solar radiation. And depending on the type of construction required by the building code, the roof structure and assembly may have to resist the spread of fire.

      Like floor systems, a roof must be structured to span across space and carry its own weight as well as the weight of any attached equipment and accumulated rain and snow. Flat roofs used as decks are also subject to live occupancy loads. In addition to these gravity loads, the planes of the roof may be required to resist lateral wind and seismic forces, as well as uplifting wind forces, and transfer these forces to the supporting structure.

      Because the gravity loads for a building originate with the roof system, its structural layout must correspond to that of the column and bearing wall systems through which its loads are transferred down to the foundation system. This pattern of roof supports and the extent of the roof spans, in turn, influences the layout of interior spaces and the type of ceiling that the roof structure may support. Long roof spans would open up a more flexible interior space while shorter roof spans might suggest more precisely defined spaces.

     The form of a roof structure whether flat or pitched, gabled or hipped, broad and sheltering, or rhythmically articulated has a major impact on the image of a building. The roof may be exposed with its edges flush with or overhanging the exterior walls, or it may be concealed from view, hidden behind a parapet. If its underside remains exposed, the roof also transmits its form to the upper boundaries of the interior spaces below.


1) Flat Roofs

•Minimum recommended slope:1/4" per foot

•Flat roofs require a continuous membrane roofing material.

•The roof slope may be achieved by inclining the structural members or roof deck, or by tapering the layer of thermal insulation.

•The slope usually leads to interior drains. Secondary,emergency overflow roof drains or scuppers are required in cases where water might be trapped if the primary roof drains are blocked. 

•Flat roofs can efficiently cover a building of any horizontal dimension, and may be structured and designed to serve as an outdoor space.

2) Sloping Roofs

•Sloping roofs may be categorized into

a)Low-slope roofs - upto 3:12

b)Medium-to high-slope roofs - 4:12 to 12:12

•The roof slope affects the choice of roofing material, the requirements for underlayment and eave flashing, and design wind loads.

•Low-slope roofs require roll or continuous membrane roofing; some shingles and sheet materials may be used on 3:12 pitches.

•Medium and high-slope roofs may be covered with shingles, tiles, or sheet materials.

•Sloping roofs shed rainwater easily to eave gutters.

•The height and area of a sloping roof increase with its horizontal dimensions.

Sunday, August 30, 2020



Location :

Located in a once-rural setting, 55 miles (89 km) southwest of Chicago, estate adjoining the Fox River, in the city of Plano, Illinois.

Architect :

         Ludwig Mies van der Rohe, born Maria Ludwig Michael Mies (March 27, 1886 – August 17, 1969) was an architect and designer. Mies has long been considered one of the most important architects of the 20th century. In Europe, before World War II, Mies emerged as one of the most innovative leaders of the Modern Movement, producing visionary projects and executing a number of small but critically significant buildings. After emigrating to the United States in 1938, he transformed the architectonic expression of the steel frame in American architecture and left a nearly unmatched legacy of teaching and building. Born in Aachen, Germany, Mies began his architectural career as an apprentice at the studio of Peter Behrens from 1908 to 1912. There he was exposed to progressive German culture, working alongside Walter Gropius and Le Corbusier. 

About Fransworth House :

        One of Mies’ most famous aphorisms was “less is more”. For many, the architecture of Farnsworth House represents the ultimate refinement of his minimalist beliefs. It was designed and constructed between 1945 and 1951 as a oneroom weekend retreat, located in a once-rural setting, 55 miles (89 km) southwest of Chicago on a 60-acre (240,000 m2 ) estate adjoining the Fox River, in the city of Plano, Illinois. The steel and glass house was commissioned by Dr. Edith Farnsworth, a prominent Chicago medical specialist, as a place where she could engage in her hobbies: playing the violin, translating poetry, and enjoying nature. Farnsworth was highly intelligent, articulate, and intent on building a very special work of modern architecture. Her instructions for Mies were to design the house as if it were for himself.

       Mies created a 1,585-square-foot (140 m2 ) house that is now widely recognized as an iconic masterpiece of the International Style of architecture. The home was designated a National Historic Landmark in 2006 after being added to the National Register of Historic Places in 2004. It is currently owned and run as a house museum by the National Trust for Historic Preservation. Like many Modernists, Mies worshiped the technology-driven modern era he lived in, but also believed that reconnecting the individual with nature was one of the greatest challenges faced by an urbanized society.. With this in mind, Mies conceived Farnsworth House as an indooroutdoor architectural shelter simultaneously independent of and intertwined with the nature around it. The simple elongated cubic form of the house runs parallel to the flow of the river and is anchored to the site in the cooling shadow of a large and majestic black maple tree. To underline the strong connection with nature, the house was deliberately built on the flood plain near the river’s edge instead of on the flood-free upland portions of the site.

         The essential characteristics of the house are immediately apparent. The extensive use of clear floor-to-ceiling glass opens the interior to its natural surroundings to an extreme degree. Two distinctly expressed horizontal slabs, which form the roof and the floor, sandwich an open space for living. The slab edges are defined by exposed steel structural members painted pure white. The house is elevated five feet three inches (1.60 m) above the flood plain by eight steel columns, which are attached to the sides of the floor and ceiling slabs. The end of the slabs extend beyond the column supports, creating cantilevers. The house seems to float weightlessly above the ground it occupies. A third floating slab, an attached terrace, acts as a transition between the living area and the ground. The house is accessed by two sets of wide steps connecting the ground to the terrace and then to the porch. As was often the case with Mies’ designs, the entrance is located on the sunny side, facing the river instead of the access road.

Facts :

Building type :- House. One-room weekend retreat 

Materials :- Steel and glass 

Style :- Modern 

Construction Date :- From 1945 to 1951 

Floor area :- 1,585-square feet (140 m2 )

Friday, August 28, 2020



         The Leaning Tower of Pisa or simply the Tower of Pisa is the campanile, or freestanding bell tower, of the cathedral of the Italian city of Pisa, known worldwide for its nearly four-degree lean, the result of an unstable foundation. The tower is situated behind the Pisa Cathedral and is the third-oldest structure in the city's Cathedral Square, after the cathedral and the Pisa Baptistry. The height of the tower is 55.86 metres (183.27 feet) from the ground on the low side and 56.67 metres (185.93 feet) on the high side. The width of the walls at the base is 2.44 m (8 ft 0.06 in). Its weight is estimated at 14,500 metric tons (16,000 short tons). The tower has 296 or 294 steps; the seventh floor has two fewer steps on the north-facing staircase. The tower began to lean during construction in the 12th century, due to soft ground which could not properly support the structure's weight, and it worsened through the completion of construction in the 14th century. By 1990 the tilt had reached 5.5 degrees. The structure was stabilized by remedial work between 1993 and 2001, which reduced the tilt to 3.97 degrees.

Architect :                                                                                                   There has been controversy about the real identity of the architect of the Leaning Tower of Pisa. For many years, the design was attributed to Guglielmo and Bonanno Pisano, a well-known 12th-century resident artist of Pisa, known for his bronze casting, particularly in the Pisa Duomo. Pisano left Pisa in 1185 for Monreale, Sicily, only to come back and die in his home town. A piece of cast bearing his name was discovered at the foot of the tower in 1820, but this may be related to the bronze door in the facade of the cathedral that was destroyed in 1595. A 2001 study seems to indicate Diotisalvi was the original architect, due to the time of construction and affinity with other Diotisalvi works, notably the bell tower of San Nicola and the Baptistery, both in Pisa.

Construction :
       Construction of the tower occurred in three stages over 199 years. On 5 January 1172, Donna Berta di Bernardo, a widow and resident of the house of dell'Opera di Santa Maria, bequeathed sixty soldi to the Opera Campanilis petrarum Sancte Marie. The sum was then used toward the purchase of a few stones which still form the base of the bell tower. 
On 9 August 1173, the foundations of the tower were laid. Work on the ground floor of the white marble campanile began on 14 August of the same year during a period of military success and prosperity. This ground floor is a blind arcade articulated by engaged columns with classical Corinthian capitals. Nearly four centuries later Giorgio Vasari wrote: "Guglielmo, according to what is being said, in the year 1174, together with sculptor Bonanno, laid the foundations of the bell tower of the cathedral in Pisa". The tower began to sink after construction had progressed to the second floor in 1178. This was due to a mere three-metre foundation, set in weak, unstable subsoil, a design that was flawed from the beginning. Construction was subsequently halted for almost a century, as the Republic of Pisa was almost continually engaged in battles with Genoa, Lucca, and Florence. This allowed time for the underlying soil to settle. Otherwise, the tower would almost certainly have toppled. On 27 December 1233, the worker Benenato, son of Gerardo Bottici, 
oversaw the continuation of the tower's construction.

Wednesday, August 26, 2020


  Villa Savoye is a modernist villa in Poissy, on the outskirts of Paris, France.

Owner :  French Government

Architect :

 Le Corbusier and his cousin, Pierre Jeanneret                                                                                                     Charles-Edouard Jeanneret (6 October 1887 – 27 August 1965), known as Le Corbusier was a Swiss-French architect, designer, painter, urban planner, writer, and one of the pioneers of what is now called modern architecture. He was born in Switzerland and became a French citizen in 1930. His career spanned five decades, and he designed buildings in Europe, Japan, India, and North and South America. Pierre Jeanneret (22 March 1896 – 4 December 1967) was a Swiss architect who collaborated with his cousin, Charles Edouard Jeanneret, for about twenty years.

“the house is a machine for living in.”

Introduction :

• A modernist villa in poissy; the outskirts of Paris.

• As the last purist villa, it is an attempt of reconciliation between the Platonic attributes of nature and man.

• Designed and constructed between 1929 and 1931 by Le Corbusier and his cousin, Pierre Jeanneret.

• Named “Les Heures Claires” by Le Corbusier.

• Commissioned as a private country residence by Pierre and Emilie Savoye in 1928. They came from a wealthy Parisian family that ran a large and successful insurance company and owned land in the town of Poissy. 

• Le Corbusier noted that his clients were: ‘quite without preconceptions, either old or new’ and only had a vague idea of what their future country house should look like. 

• Is recognized as the most faithful to his five points of architecture. 

• The Villa has become an icon of Le Corbusier’s ideals and methodology. 

Site : • Grove of trees shields from strong winds, while allowing sunlight

     • Patio receives breeze from SW in summer. It is sheltered from cold NW wind in winter. 

Architectural style : Modernist, International

Located at : Poissy, Yvelines, France.

Construction started : 1929

Construction completed : 1931

Concept :

• Purist and cubist approach

• First floor deliberately raised off of the ground so that it (as Le Corbusier put it) will be out of the wetness and damp of the earth, raising its gardens as well to provide healthy and dry garden space. 

• The textures, materials, colours and methods of emphasis of the horizontality, juxtaposed with the upward climb of the ramp and staircase combine to create an atmosphere that draws the visitor through the space.

• Facade reduced to a screening function, a skin, lending to a feeling of the structure being lighter or weightless, a principle heavily looked at by the Bauhaus at that time.

The design features of the Villa Savoye include :

•“The Five Points of Architecture”

• Modular design - the result of Le Corbusier’s research into mathematics, architecture (the golden section), and human proportion. 

• No historical ornament 

• Abstract sculptural design

• Pure color - white on the outside, a color with associations of newness, purity, simplicity, and health (Le Corbusier earlier wrote a book entitled, When the Cathedrals were White), and planes of subtle color in the interior living areas.

• Dynamic , non-traditional transitions between floors - spiral staircases and ramps.

• Integral garage - the curve of the ground floor of the house is based on the turning radius of the 1927 Citroen. 

• Inspiration from greek architecture - basic elements of classical architecture transformed. 

• Inspiration from steam ships and locomotives.

Forms :

Villa Savoye is an exploration in the use of primary forms, using rectangles, cylinders, and cubes. Le Corbusier started with a cubic volume and eroded elements to create the final form. Villa Savoye takes structural inspiration from the Domino Structure, characterized by planar slabs connected by a dogleg staircase. In the Villa Savoye, a ramp was added along with the staircase.

Five main building elements :

1) Pilotis :

2) Free facade :

• The columns are set back from the facades, inside the house. 
• The floor continues cantilevered. 
• The stilts that support the structure allow for non-supporting walls. 
• The facades are no longer anything but light skins of insulating walls or windows. 
• The facade is free.  

3) Ribbon windows :

• Reinforced concrete provides a revolution in the history of the window. 
• The second floor of the Villa Savoye includes long strips of ribbon windows that allow views of the large surrounding yard and is inspired from steam ships. 
• These strips of elongated windows allowed for impressive views of the exterior and let in a great amount of natural light – providing expanded illumination and ventilation. 

4) Open floor plan : 

• Previously, the load-bearing walls formed the structure not allowing flexibility. 
• Now, like the free facade, the open floor plan is made possible by the system of supporting stilts. 
• The open floor plan, relieved of load-bearing walls, allow walls to be placed freely and only where aesthetically needed.  

5) Roof terrace :

Functions : 
The house occupies a site in Poissy, a small commune outside of Paris, in a field that was originally surrounded by woodland. Designed as a weekend holiday home for the Savoye family. The house was originally built as a country retreat for the Savoye family. The Villa Savoye is a revolutionary building because it was designed to be functional and to revolve around people's daily lives. With its systematic efficiency, lack of ornamentation, and clean lines, the Villa Savoye exemplifies Purism and Le Corbusier's desire to simplify design.

Building elements : 
These include pilotis that lift the building up above the ground, a flat roof that could serve as a garden and terrace, open-plan interiors, ribbon windows for light and ventilation, and a free facade independent of the load-bearing structure. A row of slender reinforced concrete columns supports the upper level, which is painted white. The lower level is set back and painted green like the surrounding forest to create the perception of a floating volume above. The lower level is dedicated to the maintenance and service programmes of the house, while the living spaces are located on the upper level. Strips of windows – a common feature in Le Corbusier's work – are designed to open by sliding over each other and are placed in the middle of the facade on the upper level to bring in as much light as possible. A series of ramps, as well as a sculptural spiral staircase, connect the two floors, and are intended to provide a gradual movement between levels. On the first floor, a large sliding glass wall opens the living spaces to an outdoor terrace. From here, a ramp leads to rooftop garden, which is encased by curved walls. A large triangle of windows offers views from the ramp to the spaces inside.

Plans, Sections, Elevations :

Conclusion :

1. five points
2. golden ratios
3. purist style
4. basic forms used - cuboids and cylinders
5. machine and technology incorporated (esp. cars) - curve corresponding the turning radius of citroen.

Wednesday, August 5, 2020



     Architectural design process is the scientific study of existing ideas, thought and thinking in getting detail solution of an architectural design. It’s explained that the difference between architectural design process and scientific methods is that, architectural design is concerned with how things ought to be done while natural sciences are concerned with how things are. Generally it is considered that the difference between architectural, mechanical and industrial design processes is the aspect of the problem considered, the primary source of knowledge, the degree of commitment made to output statement, the level of detail, and finally the method of transformation. Design process is a method that reveals how things are created.

    Illustrates the composition of four different activities in architectural design. Assimilation represents the process of gathering information related to the proposed design such as verbal communication with client and documentation of the design brief. The complete analysis of design problem and the identification of most suitable design solution constitute the components of general study. The growth and refinement of tentative solutions isolated during general study is what is referred to as development. Finally, communication is the act of representation design information to design teams, client, user and general public.

    Architectural design is a combination of graphical and theoretical solution to a problem, such as residential design, industrial design, institutional design, religious design, and commercial design. The solution take the forms of plans, elevations, sections, details, perspective, graph, analysis of proposed and existing features. Table I, demonstrates stages involve in architectural design process. In solving these problems, designers’ use thinking and drawing as a tool in achieving the required creative result. Creativity and Innovation is important throughout the life span of the project. Some of its functions include generation and improvement of design idea together with improving perception of aesthetics on physical elements use for facade design. Other functions of creativity-innovation include choice and application of modern building materials.


   Designers/Architects generate analysis of their design ideas through drawings, written word and verbal expressions. Idea generation is an activity that transforms conceptual idea to concrete idea. Technique like brainstorming is commonly applied by designers for idea generation purposes. It is obvious that such a critical part of human endeavor is an important part of the design process.  

   Imagery is a mental picture in which a designer formulates in his/her mind a design and such representation comes in abstract form. The designer uses mental imagery and perception as a tool to represent his ideas at the mental stage. Mental imagery is an idea that was generated, evaluated, and transformed by the designer as a solution to a design problem. Meanwhile, perception is an idea which is triggered by a similar experiential idea either from a stored memory or perceived from the physical element of the immediate environment or the product of objects or events that exist. 

     Evidence of the importance of mental imagery in memory, reasoning and invention, and research reveal that awesome proportion of the brain is dedicated to vision. Evidence from cognitive science suggests that the mind uses imagery and verbal processes for complementary and interdependent purposes. This suggests that it may be an error to separate, as one tends to do visual or depicts from propositional mode of education. It has been scientifically indicated that visual thinking use different brain systems from verbal. When a person visualizes something blood runs faster in the visual cortex. Research carried out on patients’ show that injury to the left half of the brain can stop the generation of visual images. Mental imagery is a vital tool for brainstorming activities. It is in these activities that “mental synthesis” is employed in the process of analysis and evaluation.


    All designers are concerned with the visual aspect of their design. Some designers use mental imagery to measure and ensure their design address the intended problem. Designers visualize designs being used in every possible situation through the process of grappling with the design problem until it is finally solved. Visualization is a medium that generates design and technically presents it to the owner or client and the design team in facilitating the design process. This medium includes drawings, written word or verbal expression. Illustrates how visual representations are classified into categorical descriptions that represent abstract ideas or sign constraints and visual specific spatial depiction.


   Innovations in building materials are by no means a simple process. Initially, the material is invented or introduced, followed by testing the material, improving performance and finally expanding the development of the material. Newly innovated building materials such as carbon fiber, glass fiber, Teflon glass fabric, translucent glazing, carbon naan tubes, spider silk, Kevlar, Styrofoam are used by architects and engineers in innovating complex designs. These newly innovated building materials offered designers and engineers the opportunity to innovate all sort of complex designs.

Friday, May 1, 2020


Adhesives :

An adhesive is a material (liquid/semi liquid/solid form) that adheres/bonds at least two surfaces together in a strong and stable manner. 

Bonding in Adhesives :

Mechanical Chemical Van der Wall forces (the attraction between two molecules, each of which has a region of slight positive and negative charge) Moisture aided diffusion (Diffusive bonding occurs when species from one surface penetrate into an adjacent surface while still being bound to the phase of their surface of origin)

There are two types of sources :
1) Natural – starch, animal glue, albumen, etc. 
2) Synthetic - elastomers, thermoplastics, emulsions, etc.

Categories of adhesives :

Non-reactive - 
1. Pressure sensitive adhesives – Pressure Sensitive Adhesive (PSA) adhesives that form a bond with the substrate on application of light pressure. PSA can be of water based, solvent based and hot melt. Ex. acrylate based polymers 
2. Hot application adhesives - Hot Melt Adhesives also known as hot glue is commonly supplied in solid cylindrical sticks of various diameters, designed to be melted in an electric hot glue gun.

Reactive -
Basically the adhesives in this class are thermoplastic in nature which means they are heated to a sufficient temperature where they will flow and wet the substrates and then set and develop the bulk strength on cooling. 
1. UV Light curing adhesives- UV cure adhesives contain photoinitiator molecules which are activated and / or decompose when they absorb the energy emitted by the ultraviolet light; producing free radicals which initiate and accelerate the curing process of the adhesive achieving solidify state in order of seconds. Ex. UV Epoxy, UV Acrylic, UV Silicone, UV Cyanoacrylate, UV Anaerobic. 
2. Heat curing adhesives- When heat is applied the components react and crosslink. Ex. thermoset epoxies, urethanes, and polyimides. 
3. Moisture curing/One Part adhesives- Moisture curing adhesives cure when they react with moisture present on the substrate surface or in the air. This type of adhesive includes cyanoacrylates and urethanes.

Where are Adhesives used in Construction?

To bond ceiling, wall and floor tiles, timber and timber products, concrete, asphalt and fabrics, metals etc.

Characteristics of a good Adhesive

1. They must behave as a liquid, at some time during bond formation, to flow over and wet (make intimate contact with) the adherents. 
2. They form surface attachment through adhesion (the development of intermolecular forces). 
3. They must harden to carry sometimes continuous, sometimes variable load throughout their lives. 
4. They transfer and distribute load among the components in an assembly. 
5. They must fill gaps, cavities, and spaces. 
6. They must work with other components of the assembly to provide a durable product. 
7. They should accommodate temperature differences.

What are the advantages of using Adhesives?

a) Dissimilar materials can be joined 
b) Bond is continuous 
c) Large areas can be bonded in less time 
d) Bonding is more accurate 
e) Adhesives seal and join in one process Increased production speed 
f) Better finishing at no/low costs 
g) Choice of fast or slow curing 
h) Easily combined with other joining methods

Advantages of an adhesive bond :
1. Provides large stress-bearing area. 
2. Provides excellent fatigue strength. 
3. Damps vibration and absorbs shock. 
4. Minimizes or prevents galvanic corrosion between dissimilar metals. 
5. Joins all shapes and thicknesses. 
6. Provides smooth contours. 
7. Seals joints. 
8. Joins any combination of similar or dissimilar materials. 
9. Often less expensive and faster than mechanical fastening. 
10. Heat, if required, is too low to affect adhering materials.

Disadvantages of an adhesive bond

1. Surfaces must be carefully cleaned. 
2. Long cure times may be needed. 
3. Limitation on upper continuous operating temperature. 
4. Heat and pressure may be required. 
5. Jigs and fixtures may be needed. 
6. Rigid process control usually necessary. 
7. Inspection of finished joint difficult. 
8. Useful life depends on environment. 
9. Environmental, health, and safety considerations are necessary. 
10. Special training sometimes required. 

Sealants typically have lower strength and higher elongation than adhesives do. Many Adhesive technologies can be formulated into sealants. 

Monday, March 30, 2020


Glass as a building material :

Glass is an amorphous, hard, brittle, transparent or translucent super cooled liquid of infinite
viscosity, having no definite melting point obtained by fusing a mixture of a number of metallic
silicates or borates of Sodium, Potassium, Calcium, and Lead.
Manufactured Glass dates from pre-historic times in the Far East, India and Egypt
Little is known about the first attempts to make glass.

However, it is generally believed that glass making was discovered 4,000 years ago, or more, in Mesopotamia.
The Roman historian Pliny attributed the origin of glassmaking to Phoenician sailors.
He recounted how they landed on a beach near Ptolemais (in modern-day Israel), propped a
cooking pot on some blocks of natron (a naturally-occurring alkali substance) they were
carrying as cargo, and made a fire over which to cook a meal.

Properties of glass :

1. It absorbs, refracts or transmits light.
2. It can take up a high polish and may be used as a substitute for very costly gems.
3. Is has no definite crystalline structure.
4. It has no sharp melting point.
5. It is affected by alkalis.
6. It is an excellent electrical insulator at elevated temperatures due to the fact that glass can be
considered as an ionic liquid. The ions are not easily moved at room temperature because of the
high viscosity.
7. It has good workability. It can be blown, drawn or presses. But it is difficult to cast in large
8. It is extremely brittle.
9. It is not affected by air or water.
10. It is not easily attacked by ordinary chemical reagents.

Manufacture of glass :

Glass is produced by heating a mixture that consists largely of Sillica(silicon dioxide) and soda ash
(sodium carbonate). Soda ash serves as a flux to reduce the high melting point of silica (approz
1800 degree celcius). the melting that then takes place above 1100deg. cel. is amorphous that is virtually
nocrystals are formed. Because the structure of glass resembles that of fluids, glass is sometimes
called a "supercooled liquid"

#Raw materials used for manufacturing:
• Sodium as Na2Co3 (used in soft glass).
• Potassium as K2Co3 (used in Hard Glass).
• Calcium as lime stone, chalk and lime.
• Lead as litharge, red lead (flint glass).
• Silica arc quartz, white sand and ignited flint.
• Zinc is zinc oxide (Heat and shock proof glass).
• Borates are borax, Boric acid (Heat and shock proof glass).
• Cullets or pieces of broken glass to increase fusibility.

     1. Melting Process: Raw materials in proper proportions are mixed with cullets. It is finely powdered
and intimate mixture called batch is fused in furnace at high temperature of 1800°C this charge melts
and fuses into a viscous fluid. After removal of CO2 decolorizes like MnO2 are added to remove traces of ferrous compounds and
Carbon. Heating is continued till clear molten mass is free from bubbles is obtained and it is then
cooled to about 800°C.
     2. Forming and Shaping: The viscous mass obtained from melting is poured into
moulds to get different types of articles of desired shape by either blowing or pressing between the
     3. Annealing: Glass articles are then allowed to cool gradually at room
temperature by passing through different chambers with descending temperatures. This reduces the
internal Strain in the glass.
    4. Finishing: It is the last step in glass manufacturing.Like Cleaning, Grinding, Polishing, Cutting, Sand Blasting.

Following are process for sheet formation of glass:
1. Drawn Clear Sheet Glass: Clear sheet glass is transparent glass with 85% light transmission
with fire finished surface.
2. Vertical Drawing : The VD from a pool of molten glass which when 1m or so above the
pool level is rigid enough to be engaged by a series of asbestos faced rollers that continue to draw
the ribbon of glass up a tower some 10m high after which the ribbon is cut into sheets & washed in a
dilute acid to remove surface deposits.

3. Horizontal Drawing : The glass is initially drawn in the vertical plane but it is turned over
a roller so that it is drawn in the horizontal direction for some 60m & pass in to an annealing furnace
at the cold end of which it is cut in to sheets.
BS 952 recommends for sheet glass:
Ordinary Glazing Quality : this to be used for general glazing purpose.
Selected Glazing Quality : for glazing work requiring a sheet glass above the ordinary glazing

Classification of glass :

a. According to its manufacturing processes: Float glass, Clear glass, Soda lime glass, lead glass, Rolled glass, Crystal glass, Reinforcement
glass, Wired glass & Opal Glass.
3 steps involve: Melting, Forming & Controlled cooling- Annealing.
b. Post application processes: Offline coating glass, Self cleaning glass, Laminated glass, Chemically strengthened glass,
Thermally Toughened glass, Low- E glass
c. Post manufacturing processes: Edge treatment, Sand blasting, Acid etching, Pigmented glass, Bended glass.

Types of glass :

1. Soda lime or Soft Glass:

About 90% of all glass is soda-lime glass made with silica (sand), Calcium carbonate and
soda ash.
They are low cost, resistant to water but not to acids.
They can melt easily and hence can be hot worked.
Uses: Window glass, Electric bulbs, Plate glass, Bottles, Jars, cheaper table wares, test
tubes, reagent bottles etc.

2. Float Glass: 

Float glass is formed by floating a continuous ribbon of molten glass over a
bath of liquid metal at a controlled rate & temperature .The continuous ribbon of molten glass is then
run in to an annealing chamber in which the temperature is gradually reduced to avoid distortion of
the glass.
Float glass also known as polished plate glass.
This is truly flat glass with undistorted vision.

3. Potash lime or hard glass:

Potash lime glass is made with silica (sand), Calcium carbonate and
potassium carbonate.
They posses high melting point, fuse with difficulty and are less acted upon by acids, alkaline
and other solvents than ordinary glass.
Uses: These glasses are costlier than soda lime glass and are used for chemical apparatus,
combustion tubes and glassware which are used for heating operations.

4. Lead glass or flint glass:

It is made up of lead oxide fluxed with silica and K2CO3 is used instead of sodium oxide.
To get dense optical glasses about 80% lead oxide is used. Lead glasses has a lower
softening temperature than soda glass and higher refractive index and good
electrical properties.
It is bright lustrous and possess high specific gravity.
Uses: High quality table wares, optical lenses, neon sign tubing, cathode ray tubes, electrical
insulators, crystal art objects or cut glass, Windows and Shields for protection against X-rays
and Gamma rays in medical and atomic energy fields etc.

5. Borosilicate / pyrex glass:

It is common hard glass containing silica and boron with small amount of alumina and less
alkaline solids.
These glass have low thermal coefficient of expansion, and high chemical resistance
i.e..shock proof.
Uses: Industrially used for pipeline of corrosive liquids, gauge glasses, superior laboratory
apparatus, kitchen wares, chemical plants, television tubes, electrical insulators etc.

6. Alumino-silicate glass:

This type of glass possess exceptionally high softening temperature.
Uses: It is used for high pressure mercury discharge tubes, chemical combustion tubes and
certain domestic equipments.

7. 96% silica glass:

It is translucent, the coefficient of thermal expansion is very low hence it has high resistance
to thermal shock, have high chemical resistance to corrosive agents and are corroded only
by Hydrofluoric acid, hot phosphoric acids and concentrated alkaline solutions.
Uses: Used only where high temperature resistance is required (800°C). They are used in
construction of chemical plants, laboratory crucibles, induction furnace lining and electrical

8. 99.5% silica glass / vitreosil:

It contains pure silica heated to its melting point. It is translucent, the coefficient of thermal
expansion is very low hence it has high resistance to thermal shock, have high chemical
resistance to corrosive agents.
If Vitreosil glass is heated above its melting point, it becomes transparent and is known as
clear silica glass.
Uses: They are used in construction of chemical
plants, laboratory crucibles, induction.

9. Safety glass:
It is made by fusing two to three flat sheets of glass
and in between them alternate thin layer of vinyl plastic
is introduced.
It is heated where both the layers merge together and
glass is toughened.
Uses: It is used as wind shield in automobiles and
airplanes. On breaking it pieces does not fly apart because of the presence of the plastic
layer in between the glass layers.

10. Optical or crook’s glass:

It contains Phosphorus, PbCO3, silicates and Cerium oxide which has the property to absorb
harmful ultra-violet light.
This glass is given through homogeneity by heating it for a prolonged period of time.
These glasses have low melting point and are relatively soft.
Uses: They are used for making optical lenses.