Deck Stairs—Step By Step
By Matt Weber
I spent most of last spring building a big deck, so I wanted a big set of stairs to match. A width between seven to eight feet seemed like ample space for walking and be large enough to give the nearly 40-foot deck a visually complementary stair design. I had left the deck handrail unfinished at the stair location, which provided the upper landing, but I had to construct the lower landing on the ground from concrete, as well as everything in between. Here’s a step-by-step account of the job, from digging the slab to staining the handrail.
Start with a Plan
Laying out the staircase is the first step. The pitch of your stairs will be determined by the rise and run you need to traverse to reach the landing, factored with a comfortable tread and riser height that adheres to local building codes. (For example, maximum riser height is typically 7-3/4 inches; minimum tread depth is usually 9 inches.) Stair layout can be a complicated process, so for an in-depth look at calculating stairs, click here. Because, for this project, I cheated.
I designed these stairs for the Universal Stair Brackets from GoPro Construction. Made from 16-gauge hot-dipped galvanized steel, these brackets eliminate the need to cut stair notches, and reduce measuring and marking as you screw in the pre-marked stair hangers. It saves a lot of work. Plus, when I say that I “cheated” during the layout phase, I was referring to the free Online Stair Calculator available at www.goproconstruction.com. Simply type in your total rise and run, and the stair calculator spits out the number of risers and runs (brackets) needed, as well as stringer length, slope and tread height. Plus, with the click of a mouse you can adjust the stair slope to make it more or less steep, and the layout figures are automatically adjusted for you. I was happy to cheat.
One note about slope: Depending on the proposed handrail system of your steps, you may be limited in the range of slope you can use. For example, I was using the Deckorators handrail system with specific stair connectors that will only work on a slope of 30 to 35 degrees. You’ll need to account for such requirements when designing the stair layout.
The width of my staircase was another unusual factor. Code typically requires the stairs be supported by stringers spaced no greater than 2 feet on center, which meant my unusually wide staircase required a total of five stringers.
With my measurements provided by the GoPro calculator, I could then map out where my lower landing would be on the ground. Building a slab landing can be tough work, requiring a lot of digging and other sorts of manual labor. Be prepared for a workout if you’re tackling this job.