Let's put it all together so we can follow what it is saying.
(bold is mine, my notes/explanations are underlined)
R308.4 Hazardous locations.
The following shall be considered specific hazardous locations for the purposes of glazing:
- 1. Glazing in swinging doors except jalousies.
- 2. Glazing in fixed and sliding panels of sliding door assemblies and panels in sliding and bifold closet door assemblies.
- 3. Glazing in storm doors.
- 4. Glazing in all unframed swinging doors.
- 5. 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.
- 6. 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.
- 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 larger than 9 square feet (0.836 m2).
- - 7.2. Bottom edge less than 18 inches (457 mm) above the floor.
- - 7.3. Top edge more than 36 inches (914 mm) above the floor.
- - 7.4. One or more walking surfaces within 36 inches (914 mm) horizontally of the glazing.
- 8. All glazing in railings regardless of an area or height above a walking surface. Included are structural baluster panels and nonstructural infill panels.
- 9. 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.
- 10. 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. (Jerry's note: "Glazing adjacent to stairways ... within 36" horizontally of the walking surface and where less than 60" high above the tread". That glazing in your stairway photo meets that, safety glazing is required.)
- 11. 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: (Jerry's note: The above do not apply *IF* the following are met.)
- - 1. Openings in doors through which a 3-inch (76 mm) sphere is unable to pass.
- - 2. Decorative glass in Items 1, 6 or 7.
- - 3. Glazing in Section R308.4, Item 6, when there is an intervening wall or other permanent barrier between the door and the glazing.
- - 4. Glazing in Section R308.4, Item 6, in walls perpendicular to the plane of the door in a closed position, other than the wall toward which the door swings when opened, 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.
- - 5. 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 (730 N/m) without contacting the glass and be a minimum of 11/2 inches (38 mm) in height.
- - 6. 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 surfaces, or other horizontal [within 45 degrees (0.79 rad) of horizontal] surface adjacent to the glass exterior.
- - 7. Louvered windows and jalousies complying with the requirements of Section R308.2.
- - 8. Mirrors and other glass panels mounted or hung on a surface that provides a continuous backing support.
- - 9. Safety glazing in Section R308.4, Items 10 and 11, is not required where: (Jerry's note: Section 9 above does not apply *IF* ... the following are met.)
- - 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 1013 and 1607.7 of the International Building Code; and (Jerry's note: I.e., there is a guardrail separating the stair from the glass, if you can't fall through the guardrail, don't worry about the glass - that's all that is saying. Don't forget the "AND" right there.)
- - 9.2. The plane of the glass is more than 18 inches (457 mm) from the railing; or (Jerry's note: This one is an "OR", if this one is met instead, it's okay.)
- - 9.3. When a
solid wall or panel extends from the plane of the adjacent walking surface to 34 inches (863 mm)to 36 inches (914 mm)above the floor and the construction at the top of that wall or panel is capable of withstanding the same horizontal load as the protective bar.
(Jerry's note: I.e., instead of the guardrail in 9.1 and 9.2, you can build a solid wall 34" -36" high there where the top of the wall is as strong as the guardrail. Makes sense, right? Either the solid wall or the guardrail - either will separate the person on the stairs from the glass adjacent to the stairs.)
- - 10. Glass block panels complying with Section R610.
Those above exceptions only make sense - no need to provide safety glazing as you have now taken that safety glazing and removed it from a hazardous location. Kind of like taking a shower enclosure door and building a wall separating it from the shower - it is no longer a hazard ... right? (Of course, though, that is a bad example, because, how would you use the shower with a wall there?
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