Tutorial: Rounded Concrete Forms for Stairs



When we moved in to our house, our back porch was pretty much non-existent. It included the wood steps (but with only one handrail - we had to add the second handrail ourselves later) and a tiny concrete pad (about 3 feet by 4 feet). We added the bigger concrete pad in 2010, but we kept the wood stairs. These wood stairs were such a pain. They took up a lot of unnecessary porch space, because the top landing was so long. Not only were they a lot of maintenance (I had to stain them and seal them every spring), but they always looked like crap. The stain looked good for about 2 months and the rest of the year they looked completely dilapidated. The home builder also took a shortcut by not adding concrete under the stairs. It was dirty under the stairs and there was always garbage blowing under the stairs and there were weeds growing under them too. The worst part were the wasps. They loved those stinkin' stairs! There were always tons of wasp nests under the stairs and every time you walked on the stairs it would disturb the wasps and they would come flying out.

We had originally planned on redoing the porch with Trex wood, but that would still leave us with half the problems we had before. That's when we decided to do concrete stairs. I found a picture online of some beautiful half circle steps and that's where we got our inspiration.

We didn't totally plan on doing the steps as soon as we did, but we were talking about the project one night and went outside to assess the porch and how hard it would be to take it apart. Next thing we knew, we had the railing off and half of the porch cut apart.

Since I had stained the steps and put a coat of polyurethane on them about 4 times, a lot of the screw heads were filled with stain and polyurethane so we couldn't get the screwdriver tip into the screw head to take the stairs apart by the screws.  Instead, we brought out the circular saw and we just started cutting the porch apart.  The more we cut the porch apart, the more wasp nests we found.  It made me really glad we decided to do concrete steps instead of trex steps.

When we got the bottom step off, we realized that the concrete under the steps had an unfinished edge.  We knew that would make doing the concrete a big pain!

There was so much garbage underneath where the steps were.  If were later in the summer, there would have been a  lot of weeds too.

As soon as we had the whole porch off, I realized what a hassle it was going to be to not be able to use the back door. The kids and I go in and out of that door a million times a day. That's when we decided we'd be doing a concrete job over the weekend.

We've never done anything with concrete before, but I felt like we had a little bit of an advantage because TJ did have a class in college where he learned about concrete for an entire semester. He didn't actually  finish concrete, but he learn about the technical aspects of concrete (and who knows what else).

So, for this project, our overall cost was right around $230.00.  


Remember, the exact amount of materials you need will depend on the size of your stairs and your project - every project will be different.

- 3/8" Rebar (They were a foot long and less than a dollar each, we bought nine of them.)
- 2x8's
- 2x4's
- 1/4" Sheet Fiberboard with one side a Melamine type finish
- Screws
- Concrete (Of course.  We bought ours from Speed-e-Crete in Springville, UT.  We bought 1 yard of concrete and we rented the tools to finish it, our total was about $150.00).


- Table Saw
- Chop Saw
- Circular Saw
- Drill & Driver
- Kreg Jig (You could easily get away with not using one of these for this project)
- Rotary Hammer Drill with 3/8" Concrete Drill Bit (We rented it from Home Depot for about $50)
- Hammer (To drive the rebar into the existing concrete and foundation)
- Drill & Driver
- Wheel Barrow (to transport the concrete from the mixer to the site)
- Hand Mag (Magnesium) Float (We rented this and the rest of the concrete tools from Speed-e-Crete)
- Hand Steel Trowel
- Hand Steel Edger Tool
- Hand Broom (For the texture at the end)
- 8 Foot 2x4 (For Screeding the concrete)
- Shovel

We wanted to make sure we did the job right and we didn't take any shortcuts, so we rented a rotary hammer drill from Home Depot. First, we drilled all the holes we needed.  We drilled several into the foundation of the house.  These areas will make it so the steps don't pull away from the house.

Then, we drilled holes onto each edge of the existing concrete pad.

I thought that drilling the holes and placing the rebar would take a long time, but I was surprised at how quickly it went.

It cost us about $50 to rent the rotary hammer drill and the concrete bit, but it was worth every penny.  You didn't have to put hardly any pressure on the drill and had no problem drilling right into the concrete.

After we finished drilling the holes, we used a hammer to hammer the rebar into the holes.

It took longer to hammer the rebar into the holes than it did to drill the holes!  Overall, the whole process probably took less than an hour.

In this picture, you can see all the rebar that we added.

Once we had the porch removed, holes drilled, and rebar added, the last step we needed to do (before doing the concrete) was to build the concrete forms.  This is where the woodworking comes in!  Because we wanted our stairs to be a half circle, it complicated things just a little.  Building square forms would have been much easier.  Overall, the forms were fairly easy to build.

To build them, we bought a couple 2x8's and a sheet of fiberboard (that had a nice, white melamine-type top).  It was a very thin piece, so it bent easily.  We also bought a 2x4 that we could use as "wings" for the bigger step.  We started by building the frame with the 2x8.  We wanted our steps to be 7 inches high (we measured from our door to the ground and we divided it to figure out how to make each step an equal distance down), so we cut down the 2x8's to 7 inches tall. Each step was approximately 12 inches deep.  Then, we built the frame.  Next, we cut our fiber board to 7 inches tall as well.  Then, we laid it down flat and we bent the fiberboard until it had the rounded shape that we wanted.  We marked it, cut it to the right length (all of the measurements will depend on your exact stairs and the measurements you would want, of course), and then we marked the center of the frame and the center of the fiberboard and we lined those up and screwed it in.  Then we bent the edges and we screwed those into place as well.  The form for the top stair was finished!

The curve on the bottom step had to match the top step perfectly, but the step was so big we had to cut the fiberboard in half and do one side at a time. We knew that the curve on the bottom step poked out twelve inches from the top step all the way around. Finally, we traced the curve of the top step onto the concrete basement floor. Then, we used the measuring tape and we drew a basic curve by measuring twelve inches out from the small curve. Then, we placed the form there and we could see exactly how to bend the fiberboard to screw it in. Not only that, but the bottom step was so long that we needed to cut two different strips of fiberboard in order to make it long enough.  It was tricky, but we figured it out and the curves matched perfectly!

In this picture, we hadn't added the little "wings" to the corner of the curve on the bottom step.  We ended up doing that a little later.  Having those there would make it so that the weight of the concrete wouldn't change the bend in the bigger step.

In this picture you can see the bigger form a little bit better.  We added sides to the forms so that it could sit freestanding on the existing pad.  We also notched out a little of the bottom so we could fit our concrete tools under there to finish as much concrete as possible.

Then, we added the second step.  We made this step sit on top of the first form, and we made it so we could screw it right into the bottom form to help hold it into place.

The most exciting part, for me, was looking out the back door after the frames were in place.  It helped me visualize how those steps would look when I walked out my back door!

We woke up early Saturday morning to start our project. Rain was being forecasted for the afternoon, so we were in a big time crunch to get it done. We left the house by 8 am, stopped at McDonald's for a quick breakfast, and we made it to Speed-e-Crete in Springville by about 9 am. We went in, picked up our concrete mix, rented some concrete tools, and we were out of there by about 9:40 am.

We got home, grabbed a few things we needed (the wheelbarrow from the neighbor, a 2x4 from the basement for screeding the concrete, and Pam cooking spray to spray on the inside of the concrete forms) and got started. Renting the mixer and buying the concrete from Speed-e-Crete was the smartest thing we could have done. We ordered 1 cubic yard of concrete and, for $160 out the door, we had the concrete mixed, the mixer, and we rented tools to finish the concrete. It was worth every penny. The best part of doing it this way was not having to mix the concrete by hand and not having to shovel it in and out every time. The mixer just poured it right into the wheelbarrow.

TJ was in charge of filling up the wheelbarrow and dumping it, I was in charge of spreading it around with the shovel, and Kate was in charge of taking care of the kids inside. We all did an awesome job.

The first thing we did was the little pad at the very bottom. It took quite a bit of concrete and, as expected, that stupid unfinished edge was a little bit of a headache. We rocked it though, and figured it out.

We screeded the concrete with the 2x4 by moving it back and forth in a sawing motion. You can see from the picture above that it smoothed it out pretty good. We used the mag float to bring the cement cream to the top and push the rock down below the surface. We worked on smoothing it out as best as we could. Once we added the form for the first step, a lot of the area would be covered and we wouldn't be able to finish it anymore until we pulled the forms off.

We worked hard to finish that little edge and make it look halfway decent. The hard part is the timing. Luckily, we could turn the mixer on the concrete and it gave us a little more time to work the bottom pad.

Next, we added the first form. We started filling it up, and up, and up with concrete. We didn't know, but Kate said she was counting the whole time and we did 22 wheelbarrows full of concrete. I don't know how accurate it is, but I bet it's pretty close.  You can also see that the weight of the concrete was getting heavy.  We used the concrete blocks from under the old porch to help hold the big form into place and to keep it close to the house. It still pushed out a little bit from the house. If we had metal stakes, we would've used those to hold the forms in place.

We tried screeding the first step, but we did have quite enough concrete. So we added another wheelbarrow full. Then, we floated the concrete with the mag float and got the first step as finished as we could before we added the top form.

Then, we added the form for the second step. We screwed it into the bottom step to help it not move (we had been using concrete blocks to help hold the bottom step into place so it would slide out too). Then, we started adding concrete. We started panicking when we realized that we were almost out of concrete. TJ ran and grabbed some big rocks and we shoved those down below the top step to fill space. Phew, we made it with just enough concrete.

At this point, we cleaned out the mixer and I ran to Springville to return it.

By the time I got back, TJ had the top form pulled off and he was finishing the top two steps. The concrete was hardening pretty fast and we had to work really hard and really fast to get them finished in time. We used the steel trowels once the bleed water evaporated from the surface of the concrete. You do not want to use any steel trowels until the surface water has evaporated because the steel trowel seals the surface. If you try to finish it with a steel trowel too early, it will seal the water in the surface of the concrete and create a weak surface layer. And that is why you see scaling and spalling on a lot of drive ways. Also, spraying the surface with water will also create that weak surface layer. We did dip our float and trowel in a bucket of water while we were finishing the concrete because we got a late jump on the finishing. The concrete had hardened and we were rushing to get the surface nice and smooth.

I was getting worried they would harden before we had time to get them all finished and pretty.  I had honestly thought that it would take the steps a lot longer to harden, but they were hardening up really fast.

Luckily, since we both worked together, we were able to get them finished and we got the broom texture finished on them as well. We dipped the hand broom in the bucket of water and dragged it in one direction to create a nice looking finish. 

We did it! They aren't perfect, but we think they turned out pretty amazing for our first time doing a concrete project. It was a complicated one, doing steps (that were curved, too), but we figured it out.

So far, we are thrilled with our new stairs.  They free up a lot of space on our porch, they will require zero maintenance, and they look pretty too!


  1. Looks pretty killer. Thanks for all of the insite.

  2. the first step off the threshold has to be a minimum of 36" - what you built does not make code and potentially dangerous

    1. Yea your an ass face! Why in hell would you criticize someone that is sharing how to do something and is also proud of their work?! I'd like to say, I've worked in concrete for 18 years and I know guys and gals that's also been doing it for years and still can't form square stairs so big ups to you guys for doing this and once again your an ass face for just being a dick!! And I'm sign with my real name you puss

  3. eat a dick pal, he made steps and they look great. if you are such an expert you wouldn't be here reading about how he made steps.

  4. Valuable information and excellent design you got here! I would like to thank you for sharing your thoughts and time into the stuff you post!! Thumbs up
    Urethane concrete

  5. Thank you so much for the detailed, illustrated step-by-step tutorial. I need to do a similar project and as a first timer I find the information really helpful and pertinent.

    My thanks also to the person who pointed out the code aspect to consider so that beginner like myself must be aware of. Based on my research, other thing that could have been considered in this particular case is the addition of some moisture protection for the wood sheathing/framing behind the wall since the concrete is poured over the top line of the house foundation.

  6. Per building code in my city (Beaverton, Oregon), if this door is other than the required egress door (for a residential single-family home, usually the front-door), a "landing is not required where a stairway of three of fewer risers is located on the exterior side of the door, provided the door does not swing over the stairway." So this appears to meet code as long as the thread depth is at least 9 inches.

  7. Let me know the total cost of this work. Because after reading this post I like to have a place like this.