Well-designed steps create a great first impression, and when properly built, they will last for years. Seniorhelpline Senior Designer Michael Stillwell and his father Tony Stillwell recently designed and built steps into their barn, and shared their project with us.
The designer of any steps has a responsibility not to make them difficult or dangerous to walk down or climb. To achieve this, you must take into account an easy slope to walk up, and each step must be consistent with all of the others. A good set of steps must also stand up to the seasons—sun, rain, and snow.
The optimal slope for a human to climb is around . The slope is calculated as the rise (overall height of the steps), divided by run (the horizontal distance out from the edge of the threshold). In our case, the angle is about 29 degrees, which is shallow but not uncomfortable. Each step is 11-inches deep, and 5 9/16-inches above the next. Using 5 ½-inch wide IPE decking, we double up boards for each step.
After you've done the calculations for your steps, you can start the process of building the foundation. You'll want to dig out a couple inches below your steps and tamp it down to create a flat and even base. Pavers or bricks make a great foundation. Note that local construction codes sometimes require you to excavate the foundation to sit below the frost line, which could be several feet down. Make sure you check with the local codes in your area. In our part of North Carolina we don’t have to account for any problems caused by the ground freezing and thawing.
You can think of the design as including the threshold as the top step, making 3 steps in our case. So I only have to measure and cut the stringers (the pieces of wood that support the steps) for 2 steps.
Divide the rise (16 ¾-inches) by 3, and we are left with each step being 5 9/16-inches high, including the thickness of the IPE decking boards.
The stringers, 3 of them, are marked out on 2-inch by 12-inch pressure treated boards, with the grain of the wood running diagonally for strength. Make sure that you make all cuts square and parallel as you want the structure to sit straight and support the decking.
A table saw is useful to achieve this, but you can use a good portable jigsaw with a straight edge, and if you are feeling skillful and energetic, you may use a handsaw. In any case, mark out as accurately as you can and cut carefully to the line. You should not have to sand any surface you cut if you are accurate enough, but you may need a chisel to clean up surfaces.
When calculating how many stringers to make, allow for the decking to be supported on 16-inch centers or better.
In our case, the steps had to go in front of a 36-inch wide door, and so we used IPE decking 36-inches in length. I built a box structure with the stringers, and risers made out of 2-inch x 6-inch pressure treated boards with stainless steel screws and construction adhesive. The structure is fastened onto the skirt of the building using angle brackets and stainless steel screws.
I fastened the decking onto the structure using the same stainless steel screws (but no adhesive). You may use coated steel decking screws, but I like to over-build, since I’m not paying anyone for my labor.
Once complete, check the steps for stability and enjoy your new entry.