doors and windows

Building Materials and Construction

6. DOORS, WINDOWS AND STAIRS

Doors and WindowsA door may be defined as a framework of wood, steel, aluminum, glass or a combination of these materials secured in an opening left in a wall for the purposes of providing access to the users. The function of a door is to give access to building and to different parts of the building and to deny the access whenever necessary. Number of doors should be minimum possible. The size of the door should be of such dimension as will facilitate the movement of the largest object likely to use the doors.

A window may be defined as an opening made in a wall for the purpose of providing day light, vision and ventilation. Windows must also provide insulation against heat loss, and in some cases, against sound. The construction of window is identical to that of door. Window consists of a window frame and shutter.

Location of doors and windows1. The number of doors in a room should be kept minimum.2. Doors should preferably be placed in the corner of the room.3. If there are two doors in a room, the doors should preferably be located in opposite walls.4. The size and number of windows should be decided after due consideration to

distribution of light, ventilation and privacy of the occupants.5. The location of a window should also meet the functional requirements of the room, such

as interior decoration, arrangement of furniture, etc.6. The windows should be located opposite to each other as far as possible.7. The windows should be located in the prevalent wind direction.8. The window’s sill should be located about 70 to 80 cm above the floor level of the room.

Size of doors and windowsThe size of door depends on the requirement of the room and its size. In general, the size of door should be such that it would allow the free movement of the large object or tallest person likely to use the door. The height of the door should not be less than 1.8 m in any case. The width of the door would be 0.4 to 0.6 times the height of the door.

The following sizes of doors are normally adopted for various types of buildings:

Residential BuildingsInternal doors: 0.9 m X 2.1 m WC and bathrooms: 0.75 m X 2.1 mExternal doors: 1.0 m X 2.1 m Garages: 2.5 m X 2.25 m

Compiled by Dr. Prashanth J. and Dr. Harish N.


Public Buildings1.2 m X 2.1 m1.2 m X 2.25 m

The size of windows would be governed by the total area of window space needed. The following criteria should be kept in mind while designing the windows:

1. Width of window: 1/8 (width of room + height of room)2. There should be one square metre of window space for every 30 to 40 m3 of inside

content of the room.3. The area of windows opening should be at least 15% of the floor area of the room.

Technical termsFigs. 1 and 2 show respectively a door and a window. The following are the technical terms applied to doors and windows:

1. Frame: It is an assembly of horizontal and vertical members, forming an enclosure, to which the shutters are fixed.

2. Shutters: These are the openable parts of a door or window. It is an assembly of styles, panels and rails.

3. Head: This is the top or uppermost horizontal part of a frame.4. Sill: This is the lowermost or bottom horizontal part of a window frame. Sills are

normally not provided in door frames.5. Horn: These are the horizontal projections of the head and sill of a frame to facilitate the

fixing of the frame on the wall opening. The length of horns is kept about 10 to 15 cm.6. Style: Style is the vertical outside member of the shutter of a door or window.7. Top rail: This is the top most horizontal member of a shutter.8. Lock rail: This is the middle horizontal member of a door shutter, to which locking

arrangement is fixed.9. Bottom rail: This is the lowermost horizontal member of a shutter.10. Intermediate or cross-rails: These are additional horizontal rails, fixed between the top

and bottom rails of a shutter. A rail fixed between the top rail and lock rail is called frieze rail.

11. Panel: This is the area of shutter enclosed between the adjacent rails.12. Mullion: This is a vertical member of a frame, which is employed to sub-divide a

window or a door vertically.13. Transom: This is a horizontal member of a frame, which is employed to sub-divide a

window opening horizontally.14. Hold fasts: These are mild steel flats (section 30mm X 6mm), generally bent into Z-

shape, to fix or hold the frame to the opening. The horizontal length of hold fast is kept about 20cm, and is embedded in the masonry.



15. Jamb: This is the vertical wall face of an opening which supports the frame.16. Reveal: It is the external jamb of a door or window opening at right angles to the wall

face.17. Rebate: It is depression or recess made inside the door frame, to receive the door shutter.

Types of DoorsVarious types of doors are in use which may be classified on the basis of arrangement of shutters, method of constructions, principles of working operations and materials used. Commonly used doors are briefly explained below:

1. Battened and Ledged Doors: Battens are 100 mm to 150 mm wide and 20 mm thick wooden boards. Their length is that of door opening. The battens are connected by horizontal planks, known as ledges of size 100 to 200 mm wide and 30 mm thick. Usually three ledges are used one at top, one at bottom and the third one at mid-height. This is the simplest form of door and the cheapest also. Battens are secured by tongued and grooved joint.

2. Battened, Ledged and Braced Doors: If doors are wide apart from using battens and ledges diagonal members, known as braces, are provided to strengthen the door. Figure shows a typical battened, ledged and braced door. Sometimes above two types of shutters are provided within wooden frame work and in those cases they may be called as battened, ledges and framed doors.



Fig.: Battened and Ledged Doors Fig.: Battened, Ledged and Braced Doors

Fig.: Framed and Panelled Doors

3. Framed and Panelled Doors: This type of door consists of vertical members, called styles and horizontal members called rails. The styles and rails are suitably grooved to receive panels. The panels may be of wood, A.C. sheet, glasses etc. The panels may be flat or of



raised type to get good appearance. These are very commonly used doors. They may be of single shutter or of double shutter. Figure shows few types of panelled doors. If glass panels are used they may be called as glazed doors.

4. Flush Doors: The shutters of these doors are made of plywood or block boards. They are of uniform thickness. These shutters are available with different attractive vineer finishes. The time consumed in making such doors at site is quite less. These doors are suitable for interior portion of a building. Nowadays flush doors are commonly used in residential and office buildings. Figure shows typical flush door.

5. Louvered Doors: Whenever privacy as well as ventilation is required such doors can be used. Louvers are the glass, wooden or A.C. sheet strips fixed in the frame of shutter such that they prevent vision but permit free passage of air. The doors may be fully or partially louvered. Such doors are commonly used for public bathrooms and latrines.

Fig.: Flush Doors Fig.: Louvered Doors

Fig.: Revolving Doors



6. Revolving Doors: It consists of a centrally placed pivot to which four radiating shutters are attached. The central pivot is supported on ball bearing at the bottom and has a bush bearing at the top. The shutters may be partly or fully made up of glass. A circular space of entrance is provided within which shutters rotate. As shutters rotate they give entrance on one side and exit on other side. These doors are preferred in public buildings like stores, banks, hotels, theatres where continuous use of doors is necessary. They are very much required in entrance to air conditioned public buildings. Figure shows a typical revolving door.

Fig.: Plan of Swing Door Fig.: Plan of Sliding Door7. Swing Doors: Swing door has its shutter attached to the frame by means of double action

springs. Hence shutter can move both inward and outward. They may be single shuttered or double shuttered. Such doors are preferred in offices and banks. Since these doors can open on both sides it is desirable to provide glass panels or peep holes to enable user to see the persons from other side.

8. Sliding Doors: In this type of doors, shutter slides on the sides. For this purpose runners and guide rails are provided. Sliding shutters may be one, two or even three. Such doors are used in banks, offices etc. The arrangement of such shutters in plan is shown in Fig. 8.28.

9. Collapsible Doors: Steel channels 16 to 20 mm wide are used as verticals. They are placed with 12 to 20 mm gap. Steel flats 16 mm to 20 mm wide and 5 mm thick are hinged to them as shown in Fig. The rollers are provided at their top as well as at bottom so that shutter can be pulled or pushed sideways with slight force. There may be single or double shutters. Usually these doors are used for additional safety. They are commonly used for front doors, bank locker rooms, and school and college entrance doors.

10. Rolling Shutters: Figure shows a typical rolling shutter door. It consists of a frame, a drum and a shutter made of thin steel plates. The width of the door may vary from 2 to 3 m. The shutter moves on steel guides provided on sides and can easily roll up. For this counterbalancing is made with helical springs on the drum. The shutter can be easily pulled down. This type of doors is commonly used as additional doors to shops, offices, banks, factory, and buildings from the point of safety.



Fig.: Collapsible steel Door Fig.: Rolling Shutter

Types of windowsVarious windows used may be classified on the basis of materials used, types of shutters, types of openings of shutters and the position of windows.

1. Fixed windows. 9. Bay windows.2. Pivoted windows. 10. Clere-storey windows.3. Double hung windows. 11. Corner windows.4. Sliding windows. 12. Dormer windows.5. Casement windows. 13. Gable windows.6. Glazed windows. 14. Lantern windows.7. Louvered windows. 15. Skylights.8. Metal windows.

1. Fixed windows: In such type of windows the glazed shutter is permanently fixed in the window’s frame. This type of window is provided when light and vision is only needed in the room. No ventilation is possible through such windows.

2. Pivoted windows: In these windows, the shutters are allowed to rotate about the pivots fixed to the window’s frame. The window’s frame has no rebate. The shutter can rotate horizontally or vertically depending on the position of pivot.

3. Double hung windows: This type of window mainly consists of a frame and two shutters arranged one above the other, which can move vertically upward or downward by means of cords passing over pulleys and are connected by corner weights at other ends by open at top or bottom to the desired extent by pulling the weights suitably. Ventilation can be easily controlled by these windows.



4. Sliding windows: This type of window consists of sliding shutters which move on roller bearing and can slide either horizontally or vertically. These windows are similar to sliding doors. Such windows are provided in trains, buses, shops, bank counters etc.

5. Casement windows: It is an ordinary window, which is commonly used in residential as well as in public buildings. The shutters of the window open like shutters of the doors. The window has a frame and shutters consist of styles, top rail, bottom rail, intermediate rails, vertical and horizontal sash bars with glass panels. The panels may be glazed or partly glazed.

6. Glazed windows: This type of windows consists of shutters in which panels are fully glazed. The frame of each shutter has two vertical styles, top rail and bottom rail. The panel space between the styles and the rails is suitably divided by small wooden members placed horizontally and vertically to suit the requirements. These bars are known as sash bars or glazing bars. The sash bars have rebates to receive glass panels. The glass panels are secured in position either by putty or timber beads and nails. If the window opening is large, the window frame may have mullions and transome. These are also called as sash windows.

7. Louvered windows: In this type of window the styles of shutter are grooved to receive the louvers. The louvers are generally fixed but sometimes, the louvers can be raised and lowered by means of some operating devices. For economical construction the angle of inclination of louvers to the vertical styles should be 450. The louvers slope downward to the outside in order to run-off the rainwater. Sometimes venetian shutters are provided in which louvers are pivoted to the frame at both ends and every louver is connected by a small hinge to a vertical batten. When the batten is pulled up or down, the gap between the louvers are opened or closed. These types of windows are commonly used for bathrooms, water closets, workshops and other places where privacy is main consideration. Sometimes this window is also known as venetianed window.

Fixed windows Pivoted windows



Double hung windows Wooden casement windows

Glazed windows Louvered windows

Metal windows Bay windows



8. Metal windows: Use of metal windows is becoming very popular these days. They are used in residential as well as in public buildings. They are strong and cheap also. These windows are made from metals like mild steel, aluminum, bronze, stainless steel etc. Mild steel being cheapest of all the metals, hence steel window work out to be most economical. Mild steel sections are used for fabrication of these windows. They are available in wide range of standard sizes. The commonly used sections are angle sections, Z-sections, T-sections and channel sections. These windows are directly fixed in the masonry opening in the wall or it may be fixed into wooden frame already fitted in the window opening in the wall. Bronze, aluminum and stainless steel are considered to be the best metals for window’s construction.

9. Bay windows: A window projecting outward from the walls of room is known as bay window. This projection may be triangular, circular, rectangular or polygonal in plan. These windows provided an increased area of opening for the admission of light and ventilation. They also provide extra space in the room and improve overall appearance of the building.

10. Clere-storey windows: These windows are provided near the top of the main roof for the purpose of light and ventilation. The location of such windows are above the verandah roof, hence these are termed as clere-storey windows. These windows also improve the appearance of the building. The window shutter is horizontally pivoted and the window can be opened or closed by use of two cords, one attached to the top rail and other to the bottom rail of the shutter. To prevent the entry of rainwater in the room, it is however important that the upper part of the shutter opens inside and the lower part opens outside.

Clere-storey Window Corner Window Dormer and Gable Window

11. Corner windows: These windows are located in the corner of the room. Corner window has two faces at right angles. Due to this, it is possible to admit light and air from two directions. In addition, it also improves the architectural view of the building.



12. Dormer windows: It is the vertical window built in the sloping side of a pitched roof. It provides proper ventilation and light for enclosed space below the roof. It also improves the appearance of the building.

13. Gable windows: The window provided at the gable end of a pitched roof is termed as gable window.

14. Lantern windows: These windows are provided over the flat roofs to ensure more light and air to the inner of a building. These windows project above the roof level. They admit light from vertical faces or inclined faces. They have many shapes in plan.

15. Skylights: A skylight is provided on the sloping side of a pitched roof. The window projects above the top sloping surface. The window being parallel to the sloping surface. The skylight is provided to admit natural light to the room below of it. The opening for skylight is made by cutting the common rafters suitably. The framework of skylight supporting the glass panels consists of trimming pieces, curb frame, bottom rail and top rail. The opening so made is properly treated by lead flushing to make the roof surrounding of openings waterproof.

Ventilators: These are openings in the walls near the roof for the purpose of light and exit of foul gases. The shutter of the ventilator is horizontally pivoted and can be opened or closed by use of two cards, one attached to its top rail and other to the bottom rail. The top edge of the shutter opens inside and the bottom edge opens outside so as to prevent the entry of rainwater in the room.

Door with ventilator Window with ventilator Window with ventilator

Fixtures and FasteningsThe fixtures and fastenings of doors and windows can be if iron, brass or aluminum. They are made in different shapes and sizes to suit the requirements of different sizes and types of doors and windows. The following types of fixtures and fastenings are required for doors, windows and ventilators:

1. Hinges. 2. Handles.3. Bolts. 4. Locks.



Various Fixtures and Fastenings

StairsA structure placed between two floors that have a series of steps that allows you to move up or down freely to different level. Stairs give access from floor to floor. The space/room housing stairs is called staircase. Stairs consists of a number of steps arranged in a single flight or more number of flights.

Technical termsThe definitions of some technical terms, which are used in connection with design of stairs, are given.

Step: It is a portion of a stair which permits ascent and descent. It is comprised of tread and riser.

Tread: It is the upper horizontal projection of a step in a stair case is called tread. It is also known as going.

Riser: Vertical portion of a step providing a support to the tread. Rise: Vertical distance between two consecutive treads. String: The support to the side of the stair that holds the treads and risers in place. Waist: The thickness of the structural slab in case of an RCC stair is known as a waist. Soffit: The bottom surface of a stair slab. Flight: A series of steps without any platform, break or landing in their direction. Landing: It is a horizontal slab provided between two flights. It allows the climber to rest

before climbing again in the same direction or provides a safe place to turn and continue climbing the stair.



Nosing: The front edge of the tread usually rounded as a safety measure and now often in a different finish or material so we can define the front edge of the treads making it easier to see them, climb the stair and they often have a nonslip nosing to reduce accidents.

Baluster: The vertical member of wood or metal supporting the handrail. Handrail: A continuous rail on top of the balustrade to aid the stair user in climbing and

descending the stair. Balustrade or barrister: The combined framework of handrail and balusters. Newel Post: This is the vertical member which is placed at the ends of flights to connect

handrail. Winders: These are tapering steps which are provided for changing the direction of a stair. Scotia: It is a moulding provided under the nosing to improve the elevation of the step. Headroom: It is the minimum clear vertical distance between the tread and ceiling. Line of nosing: It is an imaginary line touching of each tread and is parallel to the slope of

the stair. Pitch or slope: It is the angle which the line of nosing of the stair makes with the

horizontal. Strings or stringers: These are the sloping members which support the steps in a stair.

They run along the slope of the stair.

Location of stairsThe stairs should be located so as to provide easy access to the occupants of the building. The stairs should well-lighted and well-ventilated and must have convenient and spacious approaches. In case of public buildings, the stair should be located near the main entrance and in



case of residential buildings, the stair should be centrally located so as to have access from all the rooms without disturbing the privacy of rooms. In case of big buildings, there may be more than one stair.

Requirements of good stairsa) Width: The width of stair should be sufficient for two persons to pass on it

simultaneously and for furniture, etc. to be carried up and down the stair. The minimum width of a stair is taken as about 800 mm. If the width of stair exceeds 1.80 m, it is desirable to provide a central handrail. Minimum width is 0.9 m in residential buildings and 1.5 m to 2.5 m in public buildings.

b) Number of Steps in a Flight: Maximum number of steps in a flight should be limited to 12 to 14, while minimum is 3. Suitable landings should be provided to give comfort and safety to the users of the stair.

c) Rise and tread: Rise and tread provided should be uniform. In residential buildings the rise must not be more than 230 mm and going of less 230 mm while in public buildings rise must not be more than 180 mm and a going of not less than 270 mm. The wider the going, the less should be the riser and greater the rise, the less should be the going.

d) Handrails: Handrails should be provided at a convenient height of a normal person which is from 800 mm to 900 mm. When a flight consists of more than three steps, a handrail at least on one side is considered a necessity. The wide stairs should be provided with handrails on both the sides. Very wide stairs, as required for public buildings, should be provided with a central handrail.

e) Pitch: The inclination of a stair to the horizontal should be limited to 300 to 450.f) Headroom: The provision of adequate headroom is a necessity in a good stair. It should

preferably not less than 2 m.g) Materials and workmanship: The stair should be constructed of sound materials and

good workmanship so as to impart durability and strength to the stair. The stairway provides a path by which fire can spread from one floor to another and hence the fire protection of the staircases is extremely important. The materials used for the linings of walls and ceiling of staircase should be non-combustible and of low flame spread.

Types of stairsThe stairs may be built with wood, concrete masonry or with cast iron. Wooden stairs are not safe, because of the danger of fire. However, they are used in unimportant buildings to access to small areas in the upper floors. Cast iron or steel stairs in the spiral forms were used commonly to reduce stair case area. In many residential buildings masonry stairs are also used. Reinforced concrete stairs are very commonly used in all types of buildings.Based on the shapes stairs may be classified as:(a) Straight stairs(b) Dog legged stairs



(c) Well or open-newel stairs(d) Geometrical stairs(e) Spiral stairs(f) Turning stairs.

Straight Stairs: If the space available for stair case is narrow and long, straight stairs may be provided. Such stairs are commonly used to give access to porch or as emergency exits to cinema halls. In this type all steps are in one direction. They may be provided in single flight or in two flights with landing between the two flights.

Straight stairs

Dog Legged Stairs: It consists of two straight flights with 180° turn between the two. They are very commonly used to give access from floor to floor. Figure shows the arrangement of steps in such stairs. Well or Open-newel Stairs: It differs from dog legged stairs such that in this case there is 0.15 m to 1.0 m gap between the two adjacent flights. Figure shows a typical open newel stair.

Dog legged stairs Open well (newel) stairsGeometrical Stairs: This type of stair is similar to the open newel stair except that well formed between the two adjacent flights is curved. The hand rail provided is continuous.


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Geometrical stairs

Spiral or Helical Stairs: These stairs are commonly used as emergency exits. It consists of a central post supporting a series of steps arranged in the form of a spiral. At the end of steps continuous hand rail is provided. Such stairs are provided where space available for stairs is very much limited. Figure shows a typical spiral stair. Cast iron, steel or R.C.C. is used for building these stairs.

Turning Stairs: Apart from dog legged and open newel type turns, stairs may turn in various forms. They depend upon the available space for stairs. Quarter turned, half turned with few steps in between and bifurcated stairs are some of such turned stairs. Figure shows a bifurcated stair.

Spiral stairs Bifurcated stairs

Fixing of rise and tread


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http://lecture.civilengineeringx.com/building/bce/Spiral-stairs.jpg

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The height of the floor is generally known. The procedure for determining the number of treads and risers is as follows:

a. The position of first and last risers is determined with regard to the positions of doors, windows, verandahs etc.

b. A convenient height for the riser is assumed.c. Number of risers = total height of floor / height of riser.d. Number of treads in a flight = number of treads – 1.

This is due to the fact that the surface of the upper floor forms the tread for the top step.

Example: Let us suppose assume that the height of floor is 3.5 m. Assuming a riser of 140 mm,No. of risers = 3.5 / 0.14 = 25No. of treads for stair with single flight = (25 – 1) = 24No. of treads for stair with double flight = (25 – 2) = 23

Depending upon the space available for staircase, the type of stair is selected.


doors and windows

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size of doors

number of doors

size of windows

location of doors

stairs doors

mexternal doors

windowsthe size of door

construction of window