I have a question about safety glass in windows. I know that the window has to meet 4 requirements in order for it to have to be safety glass.
- exposed area glazing >9sq feet
- bottom edge less than 18 inches
- top edge greater than 36 inches
- within 36 inches of a walking surface.
My question related to number one above.
Is the 9 square foot rule apply to a solid pane of glass similar to that of a sliding glass door or would a regular single or double hung window fall under this requirement also?
Dang, that .pdf looks familiar :D. James, it’s each individual glass pane that must meet the 4 criteria for safety glass to be required. So, a multi-paned window can get around the requirement if desired.
Thanks for the information. It appreciated.
Note: there is a difference between tempered glass and safety glass. You rarely see safety glass; it’s usually tempered. Be careful in your report wording so that you don’t specify “safety glass” when tempered glass will do.
The window installers here call it “tempered safety glass.”
I always thought tempered glass was a type of safety glass. It’s not?
Here some dates courtesy of Jerry Peck
Tempered Glass Locations starting with the California Code later adopted Nationwide
1961…Shower enclosures must be tempered safety laminated or wired.
1964…Glass doors, glass in doors and glass panels within 18 inches of a walking surface had to comply with the impact-rated glass if subjected to accidental human impact. Tempered-glass must be etched.
1976…Complete rewrite: Glass in doors, glazing immediately adjacent to doors, glass adjacent to any walking surface, sliding glass doors and fixed glass panels, shower doors and enclosures had to be tempered, safety laminated or wired.
1979…Wire glass no longer approved for shower and bathtub enclosures.
1982… Expanded section to include all cases where safety glazing is required: glass doors, sliding and fixed panels, storm doors, unframed swinging glass doors, shower and bath tub enclosures, glazing within 12 inches of a swinging door, fixed glass panels less than 18 inches above the finish floor and within 36 inches of a walking surface. An exemption for protective was included.
1988…No change except that glass in rails was included.
1991… Glass windows in shower or bathtub enclosures were included. Glass panels within 24 inches of the vertical side of a door were also added. Exceptions were reformatted.
1994… No changes except those glass panels forming swimming pool enclosures have to be safety laminated or tempered within 5 feet of a pool deck. Also, glazing enclosing a stairway landing or within 5 feet of the top or bottom of a stairway must be safety laminated or tempered.
308.4 #7 Glazing in an individual fixed or operable panel, other than those locations described in Items 5 and 6 above, that meets all of the following conditions:
7.1 Exposed area of an individual pane greater than 9 sf.
7.2 Bottom edge less than 18 inches above the floor.
7.3 Top edge greater than 36 inches above the floor.
7.4 One or more walking surfaces within 36 inches of the glazing.
R308.4 Hazardous locations. The following shall be considered specific hazardous locations for the purposes of tempered glazing:
- Glazing in swinging doors except jalousies.
- Glazing in fixed and sliding panels of sliding door assemblies and panels in sliding and bifold closet door assemblies.
- Glazing in storm doors.
- Glazing in all unframed swinging doors.
- Glazing in doors and enclosures for hot tubs, whirlpools, saunas, steam rooms, bathtubs and showers. Glazing in any part of a building wall enclosing these compartments where the bottom exposed edge of the glazing is less than 60 inches (1524 mm) measured vertically above any standing or walking surface.
- Glazing, in an individual fixed or operable panel adjacent to a door where the nearest vertical edge is within a 24-inch (610 mm) arc of the door in a closed position and whose bottom edge is less than 60 inches (1524 mm) above the floor or walking surface.
- Glazing in an individual fixed or operable panel, other than those locations described in Items 5 and 6 above, that meets all of the following conditions:
- 7.1. Exposed area of an individual pane greater than 9 square feet (0.836 m2).
- 7.2. Bottom edge less than 18 inches (457 mm) above the floor.
- 7.3. Top edge greater than 36 inches (914 mm) above the floor.
- 7.4. One or more walking surfaces within 36 inches (914 mm) horizontally of the glazing.
- All glazing in railings regardless of an area or height above a walking surface. Included are structural baluster panels and nonstructural in-fill panels, intervening wall or other permanent barrier between the door and the glazing.
- Glazing in walls and fences enclosing indoor and outdoor swimming pools, hot tubs and spas where the bottom edge of the glazing is less than 60 inches (1524 mm) above a walking surface and within 60 inches (1524 mm) horizontally of the water’s edge. This shall apply to single glazing and all panes in multiple glazing.
- Glazing adjacent to stairways, landings and ramps within 36 inches (914 mm) horizontally of a walking surface when the exposed surface of the glass is less than 60 inches (1524 mm) above the plane of the adjacent walking surface.
- Glazing adjacent to stairways within 60 inches (1524 mm) horizontally of the bottom tread of a stairway in any direction when the exposed surface of the glass is less than 60 inches (1524 mm) above the nose of the tread.
- Exception: The following products, materials and uses are exempt from the above hazardous locations:
- Openings in doors through which a 3-inch (76 mm) sphere is unable to pass.
- Decorative glass in Items 1, 6 or 7.
- Glazing in Section R308.4, Item 6, when there is an intervening wall or other permanent barrier between the door and the glazing.
- Glazing in Section R308.4, Item 6, in walls perpendicular to the plane of the door in a closed position or where access through the door is to a closet or storage area 3 feet (914 mm) or less in depth. Glazing in these applications shall comply with Section R308.4, Item 7.
- Glazing in Section R308.4, Items 7 and 10, when a protective bar is installed on the accessible side(s) of the glazing 36 inches +/- 2 inches (914 mm +/- 51 mm) above the floor. The bar shall be capable of withstanding a horizontal load of 50 pounds per linear foot (74.5 kg/m) without contacting the glass and be a minimum of 1½ inches (38 mm) in height.
- Outboard panes in insulating glass units and other multiple glazed panels in Section R308.4, Item 7, when the bottom edge of the glass is 25 feet (7620 mm) or more above grade, a roof, walking surface, or other horizontal [within 45 degrees (0.79 rad) of horizontal] surface adjacent to the glass exterior.
- Louvered windows and jalousies complying with the requirements of Section R308.2.
- Mirrors and other glass panels mounted or hung on a surface that provides a continuous backing support.
- Safety glazing in Section R308.4, Items 10 and 11 is not required where:
- 9.1. The side of a stairway, landing or ramp has a guardrail or handrail, including balusters or in-fill panels, complying with the provisions of Sections 1003.3.12 and 1607.7 of the International Building Code; and
- 9.2. The plane of the glass is greater than 18 inches (457 mm) from the railing.
As I understand it, “tempered glass” is difficult to break. “Safety glass” has been constructed with a film so that if it does break, it won’t shatter.
So that would seem to indicate that tempered glass is a type of safety glass because it doesn’t shatter when it does break.
Maybe they are not mutually exclusive.
Maybe all tempered glass is safety glass, but not all safety glass is tempered.
Yes, thanks Michael, I couldn’t remember who blessed us with that picture but I appreciated it.
Huh? Russel your playing with us.
Tempered glass does break and it will shatter when enough force is applied.
It is cooled in controled conditions to relieve the internal stresses in the glass.
“Safety Glass” is a sandwhich (think autoglass) that holds togethr due to the internal plastic layer.
All the tempered glass I’ve ever broken does not shatter. However, with your exclusionary statement “will shatter when enough force is applied,” that is, I believe, true of any glass. But we’re not trying to shatter the glass by using a 50-lb sledge hammer, a sawed-off shotgun, Dirty Harry’s handgun, or whatever. We’re simply trying to prevent people from falling through it. Every tempered glass door or window that I’ve seen after a person has fallen against it has not shattered. It’s merely broken into many pieces but has stayed put. In some cases, the kid walking through the tempered glass door bounced off of it with no damage to the door–saw my nephew accomplish that trick at my home back in 2000.
There are two types of safety glass - tempered and laminated (which is also tempered).
The tempering (hardening) of the glass is what causes its “popcorning” affect. The surface of the glass is heated and then cooled quickly, making it harder and brittle.
The laminating of tempered glass simply helps to “contain” the glass upon impact (picture an automobile windshield). This type is usually referred to as “safety glass” or “auto-glass.” Banks often use a multiple-layer laminated glass to stop bullets.
Laminated safety glass has two other additional benefits:
It reduces transmission of high frequency sound.
It blocks 97 percent of ultraviolet radiation.
Laminated safety glass is also used in (among other things):
Thermometers for taking body temperature
Tempered safety glass is also used in:
Liquid crystal displays (LCD’s)Skylights
My earlier post was not entirely correct. I’ve researched this a bit.
IRC R308.3 says: “Glazing shall comply with CPSC 16 CFR, Part 1201…” You can find the CPC document here if you want to further research it: http://www.access.gpo.gov/nara/cfr/waisidx_00/16cfr1201_00.html
Jeff’s description of the types of glazing is mostly correct, but his post only addresses two types of safety glazing. The scope of the CPC rule actually applies to the following: “The types of glazing materials affected by or subject to the standard are laminated glass, tempered glass, wired glass, organic-coated glass, annealed glass, and plastics.” (Sec. 1201.1)
I normally only see “tempered” glazing in windows used in shower/bath enclosures, and interior & exterior doors. I’m confused about what type of glazing is required where by the CPC, I’m tired of reading about it, and so I think I’ll change my report wording to refer to the generic “safety glazing”. If anyone knows more about this topic, please post.
That’s what I do, Joe. If I don’t find “safety glass,” then I recommend having a qualified glass professional install it, but I let that professional make the appropriate call as to what type of safety glass is required or appropriate for the specific areas.
I treat the term “glazing” similar to “service equipment” and “water closet,” prefering to use “glass,” “main panel,” and “toilet,” which are terms with which my Clients are familiar. “Glazing” is reserved for donuts. I have no idea where “water closet” came from and would be totally embarrassed to use that term in my reports. It’s a toilet. Always has been. Always will be.
Would it make sense that at one time in history, the toilet was in the closet that had no water or outside closet where it got called an out house after elaborate designs, and when water plumbing was introduced inside the house itself, it became a WATER CLOSET ha. ha.
It just might. The history of the toilet just might make some, uh, interesting toilet room reading.
is glass block in the shower still safe as gazing glass?
As safe as any other safety glass. You only need to make sure the mortar joints are sealed to prevent moisture permeating the joints and turning moldy.