Details of doors windows and ventilators

Doors, Windows and Ventilators

* The function of a door is to give access to a building or a part of it or deny access whenever

necessary. Windows ensure light and ventilation. The main idea behind providing ventilation is to

allow hot air to escape.

* Doors should be provided in the corner of the room to ensure least circulation area

The window area should be 15 to 20 per cent of the floor area. Another guideline is for every 30 m3

internal volume, there should be at least 1 m2 of window opening. The windows are located at

0.75 to 0.90 m from floor level. However, for bathrooms they may be at a height 2.0 m. They

should be positioned so as to ensure good cross ventilation. To get diffused light location of

windows is preferred on the northern side of rooms.

• Ventilators are preferably located on the underside of top floor/roof.

• Wood is a common material used for doors, windows and ventilations. Plywood is preferred for

internal doors. R.C.C frames are also preferred. For shutters glazing is with glasses. For

bathrooms PVC doors and windows may be preferred.

* Threshold is a cross wooden member of the door at floor level. Sill is the lowermost horizontal

member of a window frame. The topmost horizontal member of window/door is known as head.

Transome is the horizontal member of a frame provided to subdivided the opening. Horn is the

projection of the frame beyond the opening. Rebate is the recess made in the frame to receive the

shutter. Style is the outside vertical member of the shutter. Top rail is the topmost vertical

member of the shutter. The lowermost horizontal member of the shutter is known as bottom rails.

The middle horizontal member of shutter is lock rail. The additional horizontal rails fixed are

known as cross rails.

The area of shutter enclosed between the adjacent rails is known as panel. The light weight unit

of a frame which holds the glass within the door or window is sash bar. The vertical member

employed to subdivide a window or a door opening vertically is mullian. Louvre is a piece of

timber fixed in an inclined position within a frame. Jamb is the vertical face of the opening that

supports the frame. External portion of jamb is known as reveal. Architrave is the strip of wood

fixed round a door frame when the frame is flushed with the external surface of wall. Holdfasts

are the steel flats used to fix door/window frames with wall. They are made with steel flats of

size 30 × 6 mm wide and 200 mm long.

* Size of doors: Guideline is width = 0.4 to 0.5 times height or height = (width + 1.2) metres. In

residential buildings common sizes of doors are external doors: 1.0 × 2.0 m, internal doors: 0.9 ×

2.0 m. Bathrooms: 0.7 × 2.0 m. BIS recommends the sizes and size of frames by designation of the

form in which D is for, S for single shutter and T for double shutters. Thus, 10DS20 means size of

opening 1000 × 2000 mm door with single shutter and 12DT20 means the door with double shutter

of size 1200 × 2000 mm.

* The size of timber usually adapted are:

Frame 100 × 65 mm

Shutters—vertical style and top rail 100 × 40 mm

Bottom rail 250 × 40 mm

Lock rail 160 × 40 mm

Single panel leaf 15 mm thick

Double panel leaf 12 mm thick

* Types of doors used are: Battened and ledged, battened ledged and braced; battened ledged an

framed ledged framed and braced, framed and panelled, glazed, flushed, louvered, swing,

revolving, wire-gauged, sliding, collapsible and rolling shutter doors.

* BIS designates windows 6WS 12, 10WT12, 12WT12, 6WS13, 10WT13 and 12WT13. In the above

W is for window, S for single shutter and T for double shutter. 10WT13 means double shutter

window of size 1000 mm wide × 1300 mm high. For all those windows the size of frames and

shutters are also given. Thickness of shutters to be used are 20, 25 or 30 mm, depending upon the

size.

* Windows may be classified on the various basis:

1. Material used: Timber, steel, aluminium, etc.

2. Types of shutters: Panelled, glazed, louvered, etc.

3. Types of opening of shutters: Hinged on sides, centrally pivoted, double hung, sliding, rolling,

etc.

4. Position of windows: Bay windows, corner windows, clear storey, gable windows, skylight

windows, dormer windows.

* Ventilators: The standard dimensions of ventilators are 6V6, 10V6, 12V6. They may be with simple

brick jali work, mortar jali work or horizontally pivoted or with two glasses one fixed to bottom

of the frame and another hung from top frame with a certain gap.

* Hinges, bolts, handles and locks are the fixtures and fasteners for doors and windows.

Lintel and Arches

* Lintel and arches are provided wherever it is necessary to support a wall over an opening. The

width of lintel is same as that of wall. The end bearing for lintels should be greater than 100 mm,

depth of lintels should be span.

* Types of lintels according to materials used are timber lintel, stone lintels, brick lintels, steel lintels

and R.C.C. lintels. R.C.C. lintels may be cut lintels, continuous lintels, and lintels with sunshades

(chajjas).

* Arch is a curved intel in vertical plane. The various terms used with arches are:

Voussoirs : Wedge-shaped units forming the course of an arch

Arcades : It is the row of arches supported on piers and carrying a wall over it.

Springing points : The points from which the curve of an arch springs.

Springing line : The imaginary line joining the two springing points of on arch.

Intrados : This is the inner curve of an arch.

Extrados : This is the outer curve of an arch.

Key : This is the wedge-shaped unit at the crown of the arch.

Spandril : It is the space between the extrados and the horizontal line through the crown.

Skewback : This is the arch inclined surface on the abutment from the arch springs.

Import : This is the projecting course on the upper part of a pier or abutment stressing the springing line.

* Types of arches:

1. On the basis of shape. Flat arch, segment arch, semicircular arch, semi-elliptic arch, horseshoe

arch, pointed arch, stilled arch, venition arch, florentine arch, relieving arch, inverted arch.

2. On the basis of number of centres: Bullseye arch, three-centred arch, four-centred arch, five-

centred arch.

* On the basis of materials used: stone arches, brick arch and concrete arch. Stone arches are further,

classified as rubble arches and ashlar arches. Brick arches are further classified as rough brick

arch, axed brick arch, hinged gauged brick arch and purpose made brick arch. Concrete arches are

classified as concrete block arches, monolithic concrete arch and R.C.C. arches.

* Construction of arch involves three steps namely, installation of centring, laying of arch and

removal of centring. Decentring may be by using wedges or by sand box method.