A touch of glass

Jagvir Goyal.

Recent years have seen a rapid increase in consumption of glass in buildings. High-end hotels, high rise buildings housing modern offices and corporate houses have started making immense use of reflective glass, structural glazing and curtain walling. While glass remains the major material in design of facades of all types of commercial and office buildings, the residential sector is not left behind. Its use in houses is no more restricted to window panes only. People like to use glass every where including doors, stair railings, terrace railings, decorative features, partitions and other suitable locations. Let's therefore have a look at various aspects related to use of glass in houses:

Types of glass: Many types of glasses are now used in the houses. These include plain glass, toughened glass, tempered glass, textured glass, etched glass, stained glass, fusion glass, glass with patch work, crystal glass and one way glass. Each type of glass has its peculiar features, there are vast differences in cost and one has to choose the type of glass for each component of house very carefully.

Glass for windows: No doubt, window panes steal the major percentage of glass quantity used in a house. In the modern houses, the size of windows has increased considerably with window sill level just 6 inch above floor level and top level at 8.5 feet above the floor level. The glass used in windows is either simple float glass or toughened glass. With the increase in size of window panes, toughened glass has become a compulsory choice now. Due to large size of window panes, thickness of glass panes has also increased. Earlier, window panes used to be 4 mm to 5 mm thick. Now a days, 8 mm thick glass is chosen for most of window panes. 8 mm thick toughened glass panes look quite heavy and sturdy. For window panes of size up to 5 sq feet, one may choose 5 mm thick glass and for larger panes, 8 mm thick glass is the choice.

Toughened glass: Toughened glass used in window panes is produced by giving thermal or chemical treatment to the normal float glass. Most of the industries engaged in toughening of glass use thermal treatment only. Stresses are produced in the surface layers of glass during this treatment and these stresses lend strength to the toughened glass. It is also called tempered glass. On toughening, the strength of glass increases by about five times. While providing toughened glass in window panes, care is taken that the exact sizes of window panes is worked out through physical check at site before the toughening of glass as the glass once toughened, can't be cut or altered or grinded. It has also to be kept in mind that no holes are driven in toughened glass as any such attempt leads to the crumbling of toughened glass.

Engage the glass supplier: Like many other items such as wood work, paint work, plumbing work, electrical work etc, supply and provision of various types of glass in the house has become a separate item and a separate contractor has to be engaged for glass work. Such a contractor will visit the house, discuss various types of glasses to be used in the house, will suggest their suitability along with the thickness of glass at different locations, will take physical measurements, will get the glass toughened and fixed in position after arrival of various glass pieces that are cut to size as per measurements taken at site. He will show various books on glass design, get the design selected, negotiate rates for each type of glass and for each thickness also as rates of glass increase substantially with the increase in thickness of glass.  

Glass for beauty: Etched, painted, coloured and stained glasses are used to add beauty to the building components. Glass with patchwork looks beautiful in partitions, doors, railings. Though cost of glass increases substantially when any type of such work is got done on the glass yet people prefer to spend money on using such glass that serves architectural purposes and adds grace and aesthetic factor to the house components. Technically, one should prefer to choose west and south-west face window panes with tainted or colored or painted glass to avoid direct sunlight.  

Glass and environment: Selection of right type of glass can help a building become green and contribute towards environment protection by reducing the air conditioning load in the buildings. Glass can help in letting light enter a building but stops the heat from entering it thus helping in reducing air conditioning load. It can help in providing natural day lighting and promote energy conservation. It is recyclable and non-toxic and thus again environment friendly. Double glazed windows can help in insulating a building from heat and UV rays. Due consideration to the Solar factor of glass, its U-value, its relative heat gain and its sound insulation may help in choosing the right glass and also in saving the environment.

Use silicone in glass fixing

Toughened glass used in window panes has to be handled very carefully. Care has to be taken that its edges don't get damaged during installation of glass panes. Edges of toughened glass are in stress and the glass pane shatters if the edges get damaged during installation. Even a little extra stress on the glass pane in case of use of glass holders leads to shattering of glass. Glass panes are fixed in position by using silicone. Silicone filled tubes are used by applying silicone in the window rebate in a uniform manner. Any quantity of silicone oozing out of groove is carefully cleaned.

— The writer is HOD and Engineer-in-Chief, Civil Engineering Department in a Punjab PSU