Here are the common dimensions used for building concrete steps safely: (check with the building codes of your city to be certain)
Plan your dimensions
A. Figure the total rise - measure the height from the top of the stairs to the bottom of the stairs
B. Figure the number of stairs you will have - divide the total rise (answer from step A) by the individual rise you plan to use (typically 7 inches). Round this number off. This is the number of steps you will have.
C. Figure exact dimension of each individual rise - To do this you will divide total rise (answer from step A) by the number of steps (answer from step B.
D. Decide how deep you want each tread to be (the individual run - typically 10-12 inches.
E. Figure the total run (where the stairway will end) - To do this, multiply the individual run (step D) by the number of steps you have (step B).
- When building concrete steps, construct forms so that there is an expansion joint between the stairway and walk. - Slope 1/4 inch per running foot for the landing and 1/8 inch per foot for each tread to prevent rain and ice from gathering.
F. Purchase 3/4 inch plywood that is at least as long and wide as your stairs will be (Step A and Step E)
Make and install the step's side forms
A. Draw lines on a 3/4 inch plywood showing total rise and total run. Allow 1 1/2 inches for the riser forms at the end of the landing. Mark the end of the landing and draw lines here to establish the location of the finished treads and risers.
B. Set the side forms in place at your entryway. Use a framing square to make sure that they are perpendicular to the building foundation.
C. Check the forms for proper slope and make sure that the forms are level with each other.
D. Support the forms with 2 X 4 stakes that you pound into the ground with a sledgehammer.
E. Nail or screw the forms to the stakes.
Make and install the step's riser forms
A. Cut 2X lumber (will either be 2X6 or 2X8) to the correct width and length for your risers.
B. Using a circular saw bevel (cut at a 45 degree angle) the outside bottom of each riser (except for the lowest riser), but leave 1/8 inch of each bottom un-beveled for strength. This bevel makes it easier to use trowels to finish the tread after the concrete is poured.
C. When building concrete steps, install the top riser first and work down. Use at least three double-headed nails or screws to fasten them to the side forms.
Reinforce the forms - The weight of wet concrete exerts great pressure on your forms. When building concrete steps, support the form at all points where it may bulge.
Pouring concrete steps
Finishing concrete steps
Pull the forms when the concrete is firm enough so that the corners don't fall. But make sure you pull the forms as soon as possible so that there is time to magnesium float the sides and fill-in voids.
Concrete steps are one of the hardest concrete projects to finish. Make sure that you have someone with finishing experience help you with this part.
If you live in the Minneapolis and surrounding suburbs area, and are building concrete steps, request a bid.