FENCING:
When installed stairs must:
- have the treads installed perfectly level to ensure occupant safety
- be securely fixed in place, preferably screw or bolt fixings
- have tread and riser dimensions that ensure the safety of users
- be fitted with handrails (for the safety of the users) which comply with the NZBC.
As it is convenient for stair to be installed as soon as the builing is closed in, it is important that they are protected from damage during remaining construction and finishing work.
RAMPS:
Basic Building Access Ramp Specifications & Safety Defects
Here we discuss and illustrate the requirements for safe, useable interior and exterior access ramps in buildings. Readers should note that the design specifications for permitted slope and other specifications for ramps that are not used for building entry or exit, such as curb cuts, are different from those used at building entrances. For example a steeper slope may be permitted on non-access ramps. For complete details about building access ramp construction: slope, width, railings, non-slip surfaces, steps, landings at ramps, etc. see the standards, code, and ADA references at the end of this document.
Building Access Ramp Slope or Pitch
The combination of a sloped surface with conditions that can make that walking surface slippery, especially at outdoor building access ramps, forms a falling hazard at both ramp ascent, and ramp descent for nearly everyone. These hazards are particularly increased if the ramp pitch is too steep. The desirable ramp slope standard, one inch of rise in 12 inches of run (about 8.3 percent slope), has been adopted by most building codes regardless of whether or not the access ramp is specifically for people with disabilities.If a building access ramp (also called an egress ramp) is located within an accessible route of travel and is used as a means of egress (exiting from a building), the ramp slope should be 1:12 (4.8 degrees, 8.3 percent) or less in the direction of travel. This standard is reflected in at least four building standards: UBC 1003.3.4.3, BOCA 1016.3, ADA 4.8.2, IBC 1010.2, and is elaborated in an excellent book that we recommend on stairs and ramps, Slips, Trips, Missteps and Their Consequences, by Bakken et als.
If the ramp is NOT located within an accessible route of egress (say a ramp giving access between the street and an elevated sidewalk), the slope of the ramp may be a little steeper (1:8 rather than 1:12, or 7.1 degrees, or 12.5 percent) in the direction of travel.
Incidentally, depending on terrain, a ramp may slope upwards towards a building entry/exit door, or it may slope downwards towards the entry door. In either case, the ramp slope rules and standards are the same and the trip/fall hazards are essentially the same.
Measuring the slope of a ramp is simple:
- Project a horizontal line (use a string, level, and stake if it helps) outwards from the uppermost end of the ramp - say the building entry platform - and the end of the ramp. Keep this line dead level.
- Measure the Ramp's Rise: Measure the height (the vertical distance) from the horizontal line to the ground surface at the end of the ramp or its landing platform. This is the total rise of the ramp.
- Measure the Ramp's Run: Measure the ramp's total horizontal distance from one end of the ramp to the other - say from the point at which the ramp reaches a level building entry platform or entry door to the opposite end of the ramp.
- State the Resulting Ramp Slope: Simply write the total rise divided by the total run to express the slope as a percent (1 inch of rise / 12 inches of run = 8.3% slope), or write the slope as a ratio such as 1:12, also expressed as "one in twelve".
Ramp Slope Example 2: If the ramp is twelve feet long (144 inches) and the total rise is four feet (48 inches) then the slope of the ramp is 48:144, or simplifying by dividing both sides of the equation by 12, the slope of this ramp is written as 4:12 (and the ramp is too steep, likely to result in a fall).
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