WOOD: Wood exposed to the weather or to damp locations must be either pressure treated or naturally resistant to decay (Redwood, Cedar, Heart of Black Cypress, etc.)
FASTENERS: Nails, screws, lag bolts and so on must be rust resistant. Commonly available fastener materials include galvanized coatings, epoxy coatings, and stainless steel.
STAIRS: Several specialty stairway designs (winding, circular, and spiral stairs) may not be used in commercial applications but may be used in residential buildings. It's best if you check with the building department with your specific stair design and application.
The minimum width of stairways is 36". Handrails may project into the required width a distance of 3 ½" from each side of a stairway. Stringers and other projects such as trim and similar decorative features may project into the required width 1 ½" on each side.
RISE AND RUN OF STAIRS
Rise: Minimum rise is 4", maximum rise is 7" (7 3/4" maximum for residential).
Run: Minimum run is 11" (10" minimum for residential).
Landings must be at least as long as the required stairway width (36" for most residential stairways). With certain exceptions, landings must be located at all doorways. Stairways may not rise more than 12 feet without a landing. For example, if a stairway rises a total of 14 feet, a landing needs to be located at or near the 7 foot point.
Open sides of landings, ramps, balconies, porches, stairs, or decks which are more than 30" above grade, or the floor below, must be protected by guardrails.
Height: Residential guardrails need not be higher than 36" above the walking surface. Commercial minimum height is 42". "Ladder" effects of built-in seating or horizontal guardrail members need to be avoided.
Openings: Open guardrail and stair railings shall have intermediate rails or an ornamental pattern such that a sphere 4" in diameter cannot pass through.
Residential stairways must have handrails on at least one side. Handrails are also required on "open" sides of stairways. If both sides of a stairway are open, a handrail is required on both sides.
Height: Not less than 34" nor more than 38" above the nosing of the treads.
Other: Handrails must extend not less than 12" beyond the top and bottom risers. Handrail ends shall be either returned or terminated in newel posts or safety terminals. Handrails may terminate plumb with the nosing of the top and bottom risers in residential construction. The hand grip portion of handrails shall not be less than 1 ¼" and not more than 2" in cross sectional dimension.
The hand grip portion of handrails shall have a smooth surface with no sharp corners. Handrails projecting from a wall shall have a space of not less than 1 ½" between the wall and the handrail.