Frequently Asked Questions (FAQ)

Question:
What is the stair requirement for riser height and tread depth? Also, for the truss loading, is there a specific wind design method? What is the Exposure Category? Is there a Live Load (Ground or Roof psf)requirement? What is the wind velocity in Miles Per Hour?

ANSWER:
Chapter 10, Section 1003.3.3.3 of the Los Angeles County Building Code states the following: The rise of steps and stairs shall not be less than 4 inches nor more than 7 inches. The greatest riser height within any flight of stairs shall not exceed the smallest by more than 3/8&.the run shall not be less than 11 inches as measured horizontally between the vertical planes of the furthermost projection of adjacent treads or nosings. Stair treads shall be of uniform size and shape, except the largest tread run within any flight of stairs shall not exceed the smallest by more than 3/8 inch. Exceptions for private steps and stairways serving an occupant load of less than 10 and stairways to unoccupied roofs may have a maximum rise of 8 inches and a minimum run of 9 inches. Finally, risers adjacent to a public way, walkways or a driveway serving as a landing can have risers less than 4 inches in height with restrictions on the variation in height from the top and bottom risers.

You may review the building code over the counter at the Antelope Valley Building and Safety District Office indicated below.

Wind exposure design requirements vary based on the region, please contact a building plan checker from the Antelope Valley Building and Safety Office at (661) 723 4440 for design criteria in your area.

County of Los Angeles Department of Public Works
Building and Safety Division
335A East Avenue K-6
Lancaster
(661) 723 4440



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