The keys to building concrete steps are taking time to have the proper set up of the forms and finishing of the concrete. This article describes how to build concrete steps that are 3 risers high or less.
Keep reading to learn how to build concrete steps.
brief how to
In this article, you will find information about:
When building concrete steps, or any steps, the first step is to figure out the floor to floor height and the length of the stairway. These dimensions are calculated by finding the floor to floor height and dividing it by the number of risers and adding up the up the lengths of the treads. Exterior concrete steps are most comfortable with a 12" tread and a riser height between 6 to 7 3/4" with 7 1/2" being the most desirable.
How To Figure Out The Riser Height:
How To Figure Out The Total Run Of The Stairs: If you are using the top landing as the last tread then there will be one less tread than there is risers. For a simple 3 riser set of concrete steps there will be 2 treads.
Figure Out The Width Of The Stairs:
When you build concrete steps plan on making the steps at least 6" wider than the door it is in front of and may be wider if you desire. Code requires that they are at least 36" wide but they are more comfortable when they are wider than the doorway.
Landings: If you are pouring a concrete landing at the same time as building the concrete steps remember that the landing must stick out from the house 36" and be at least the width of the door. (09 IRC, 311.3). But it is generally best to make the landing and steps 6" wider on each side of the door.
Codes Relating To Building Concrete Steps: There are some basic code requirements relating to the tread depth and riser heights of stairs. Your local building department may enforce another code so check with them before building. The requirements that apply to building concrete steps in the 2009 IRC (International Residential Code) are as follows:
Stair Height Example: If you have a floor to floor distance of 22 1/2" inches then you will have 3 risers at 7 1/2 inches each. With 2 - 12" treads there will be a run of 24" (unless you put an angle on the face of the steps and then the total run will be less)
After you figure out the floor to floor height and the run length of the steps you will next prepare the ground to hold the concrete. The dirt should be compacted very well. If the soil where the stairs are going to be poured has been dug up recently then you should rent a mechanical compactor and compact the soil. Concrete stairs are very heavy and will sink if the earth is not properly compacted and proper drainage is allowed away from the stair location, even then there are no guarantees when you build concrete steps so make sure you do everything you can to get the soil compacted properly, there is nothing worse than building concrete steps that sink and / or separate from the house. It is common to compact the soil and then put a pile of dirt or hay bale under the stairs to save on concrete and weight.
There is no image of this but if the stairs are being built up against wood then metal flashing should be installed from the door down to 2 inches below the top of the foundation. It should extend out from the sides of the stairs at least 2 inches past the edge of the concrete.
Wood forms are what holds the sides of the steps when the concrete is poured. They are typically built out of 1/2" OSB (Oriented Strand Board ) and 2x4's. It is easier to build concrete steps using form panels than to use lumber stacked up.
step 5 Set The Panels In Place
The wood panel forms are a key component to building concrete steps. They will hold the heavy concrete while it sets. These are the steps to setting the form panels in place when you build concrete steps:
step 6 Install Steel Reinforcing
To hold the concrete steps to the house you should always drill 1/2" holes into the concrete foundation and hammer in 1/2" rebar. Use the hammer drill with a 1/2" drill bit to drill holes 4" deep and about 8" apart along the wall. Make sure the holes are at least 4" from the outside edges of the stairs and landing.
Using the riser heights that you decided on in step 1 draw the stair riser and tread outlines on the inside of the form panels. These marks are used to install the stair risers and will be the level of the top of the concrete when it is poured.
Cut the riser boards to length and nail them to the form panels by driving nails from the outside of the panels into the ends of the riser boards. A 2x8 board is actually 7 1/4" in height and often works well for the riser board without needing to be cut. To get the riser height perfect you will need to rip a 2x10 board to the exact riser height. If the form panels are not long enough to fit in all the stair treads then you can extend the form using 2x10 boards as shown in the image below.
When it comes to bracing concrete forms you can never have too much bracing. Concrete is very heavy and will blow out a form if the form has an area that is weak. If you are in doubt then add another stake or angled brace.
Tip: Ask the concrete truck driver what they think, they have watched a lot of forms blow out and have an idea of what looks strong.
After everything is set up you are now ready to pour the concrete. Make sure to keep a pile or bucket of concrete so you will have extra cream when you rub the faces of the risers, see step 10
When building concrete steps each part of the troweling process is done multiple times as the concrete cures to bring out the best finish. As the concrete hardens the tools are able to put a "tighter" finish on the surface.
After the concrete is set up enough you will remove the stair riser boards. DO NOT REMOVE THE FORM PANELS! These are the steps to finish the faces of concrete steps:
This image shows removing a form board from the face of a porch cap but the process is the same.
Use the mag trowel to rub the face of the riser. It helps to use concrete cream that you saved when pouring the steps. There will be pock marks on the face. Put cream on the mag trowel and rub it into the holes and imperfections.
Use the edger to clean up the edges again.
Broom the surface: Use a concrete broom to put the final finish on the concrete steps:
After the concrete has set up for 24 hours you are ready to cure it. This is a often overlooked step but will produce a much stronger set of stairs.
Enjoy your new steps!