Bldg & Const. - Chapter 17 - Glass & Glazing

Front 1

What are the advantages of float glass over drawn glass? over plate glass?

Back 1

The advantages of float glass over drawn glass are the quality of the glass and the economical process. The advantage of float glass over plate glass is the cost. The float glass and plate glass have virtually the same optical quality.

Front 2

Name 2 situations where you might use tempered glass?

Back 2

store-front glass
glass walls for squash and handball courts

Front 3

Name 2 situations where you might use laminated glass:

Back 3

skylights
hospital rooms (requiring a better barrier to transmission of sound than solid glass).

Front 4

Name 2 situations where you might use wired glass:

Back 4

- between a school industrial shop area and the cafeteria
- in an industrial area between two flammable areas.

Front 5

2. Name two situations in which you might use each of the following types of glass:

(d) patterned glass

Back 5

• in a bathroom area
• in an office area

Front 6

2. Name two situations in which you might use each of the following types of glass:

(e) reflective glass

Back 6

• large buildings of glass (such as office buildings) to reduce the glare
• West facing windows in Arizona to cut down on glare & cut down on solar heat gain.

Front 7

Name two situations in which you might use each of the following types of glass:

Back 7

(f) Polycarbonate plastic glazing sheet.
• Domed glazing for skylights
• Used as windows in buildings where vandalism is a problem

Front 8

3. What are the design objectives for a large-light glazing system?

Back 8

I. To support the weight of the glass in such a way that the glass is not subjected to intense or abnormal stress patterns
II. To support the glass against wind pressure and suction.
III. To isolate the glass from the effects of structural deflections in the frame of the building and in the smaller framework of mullions that supports the glass.
IV. To allow for expansion and contraction of both glass and frame without damage to either.
V. To avoid contact of the glass with the frame of the window or with any other material that could abrade or stress the glass.

Front 9

. In what ways does a typical building code regulate the use of glass, and why?

Back 9

• Building codes concern themselves with several functional aspects of glass: it’s structural adequacy against wind and impact loads; its role in providing natural light in habitable rooms; its breakage safety; its safety in preventing the spread of fire through a building; and its role in determining the energy consumption of a building.
• In coastal regions where hurricanes are common, building codes often include special requirements for resistance to the impact of objects that may be blown against glazed areas by high winds.
• The IBC, while permitting the use of artificial illumination alone, encourages the use of natural light and requires that each room have a net glazed area equal to at least 8% of its floor area. Minimum ceiling heights are established in a nearby section of the code, in part to assist in the propagation of natural light by successive reflections and diffusions within the room.
• Breakage safety is regulated in skylights and overhead glazing, to avert accidental injury that might be caused by falling shards of broken glass. Laminated glass and plastic glazing sheets, because they will not drop out of the skylight if broken, are the only skylight glazings that are permitted without restriction.
• All-glass walls have codes which mandate how much should be glazed with tempered glass, laminated glass, or plastic glazing materials.
• Fire-rated glass must be used for openings in required fire doors and fire separation walls. The maximum areas of glazed openings in these locations are specified by building codes. Most codes also require that windows aligned above one another in bldgs over 3 stories in height be separated vertically by fire resistive spandrels of a specified minimum height, usually 36 inches.
• Glass and energy consumption codes generally offer 2 approaches: Prescriptive requirements that spell out clearly the maximum amt of glass that may be used, expressed as a percentage of the overall wall area, and the minimum thermal resistance of the glass. The alternative is to do a detailed energy study of the entire building using approved methods of analysis and to show the building as a whole meets code requirements for energy conservation.