Glass and Glazing

Glass 

The various types of glass used in the construction of doors and windows are described below. 

Plate Glass 

This is a transparent and flat glass having plain polished surfaces and showing no distortion when objects through it are viewed at any angle. Show windows, picture windows and exposed windows in costly buildings are fitted with this type of glass. The thickness of plate glass varies from 3 mm to 6 mm, however, 6 mm thickness is usually preferred for use in windows. 

Clear Window Glass 

This is a transparent, relatively thin flat glass having plain and smooth surface but small waviness 'of surface is present which is visible when viewed at an angle. The thickness varies from 2.5 mm to 7.5 mm. 

Obscured Glass 

One side of this glass is patterned while rolling is being done during the manufacturing process, which obscures direct vision but does not obstruct light. Figured glass or rough cast glass are examples of this type. 

Processed Glass 

These are of three kinds, i.e. ground glass, chipped one process and chipped two process. There are many patterns available; and some patterns provide true privacy with uniform diffusion of light while others give maximum transmission of light. 

Wired Glass 

Rolled flat glass having wire mesh embedded in it is called wired glass. This is used where slight degree of fie protection or safety against any breakage is desired. 

Prism Glass 

This has prism shaped ribs for deflecting light. The prisms with different angles are available to suit various needs. 

Active Glass 

This reduces heat and a large percentage of glare. Also it transmits lesser amount of ultraviolet rays which bleach some coloured fabrics. 

Quartz Glass 

This transmits ultraviolet rays and is used in hospitals where maximum benefit from sun's rays is desired for the health of the patients. 

Bullet Proof Glass 

This is made of laminated plate glass which, may break under impact but will not shatter. 

Glazing

The process of placing glass within sash bars is called glazing. Rebates of about 6mm depth are provided on one side of the sash bars to support the glass pane. After the glass is placed in position, it is maintained there by means of putty, glazing beads, strips or moulds of wood. Windows are sometimes provided with two thicknesses of glass with an air space between them. This is called "double glazing" and is adopted in air-conditioned buildings.