The most important
building code to keep in the back of your mind, for working with outdoor
stairways is to make sure that water does not accumulate on any part of
the stairs. This can be a bigger problem than anyone could ever imagine,
especially in areas where it rains often.
Stairway walking surfaces shall not exceed 1:48 or 2% slope in any direction. This formula breaks down to a quarter of an inch per foot. Remember that this is the maximum sloping surface for any part of the stairway that someone can walk on. This would include all floors, landings and stair treads.
Outdoor stairways shall be designed so water will not accumulate on the stairway steps. This would include all floors, landings and stair treads.
Stairways subjected to snow and ice shall be protected to prevent the accumulation of snow and ice, on any stairway. This particular building code could cost builders a small fortune. It costs a lot of money to cover a stairway with a roof.
Special Tip: These building codes make sense, because water accumulation on certain building materials can make them extremely slippery. Remember, building codes main function is to keep people safe.
One Inch Per Foot Slope