David Gatti and I continue our conversation about building steps in the yard. This segment of the interview focuses on building concrete steps, specifically.
Q. How do concrete steps and decorative stone steps compare regarding costs, design, durability, etc.? Please focus on the more formal type of concrete steps (as opposed to, say, making precast concrete stepping stones).
A. Concrete steps cost about $300 per step to be installed as opposed to $150 for a stone step. While concrete as a material may be cheaper than stone, it is much harder and more time consuming to install. On average, it takes about two full days to lay concrete steps, but only half a day for stone stairs. The prep and installation of concrete is also much more meticulous because there is more room for error.
I also tend to prefer stone over concrete steps because of the aesthetics and durability. Stone is more durable, as concrete tends to crack unless laid perfectly, and it is available in more shapes and colors than concrete. So, especially when considering a DIY project, I recommend stone for outdoor steps. Stones and pavers can also be replaced if needed, while concrete steps would need to be re-poured. If a homeowner is looking to install a more formal outdoor stairway, then I recommend pavers because they are much stronger than mixed concrete at 9500 PSI.
Q. Would you consider installing concrete steps a viable do-it-yourself project?
A. I would not recommend installing concrete steps; this type of project is very labor intensive and involves quite a few minute details that can make or break the final product.
Q. How far down do you have to excavate to lay the groundwork for concrete steps?
A. Excavation to lay the ground work for concrete steps should go at least 6-8 inches. Or, if you live in colder weather, you will need to dig around 18 to 20 inches.
Q. Give my readers a brief orientation in terms of initiating the installation. For example, would you begin work at the bottom or the top of the eventual flight of concrete steps?
A. Homeowners should use 1x6 or 1x8 pieces of pine wood to create rectangular boxes 16 inches deep and 4 ft wide. Leave the back side open. Use a sledge-hammer or mallet to drive each box horizontally into the ground where you want each of your steps. A homeowner should stake each side of the boxes to keep them in place and screw or nail the stakes from the inside out. Add rebar for each concrete step for added support. You will then use a monolithic pour, which is a continuous pour for even concrete. A pump truck is helpful for this type of project because using a wheelbarrow can be difficult and timing is essential.
Work from the bottom toward the top, and use a trowel to smooth the tops of the concrete steps as you go. Then, you’ll need to remove the wood boxes. Timing is essential for this part, as you want to wait until the concrete is dry enough to keep its form but wet enough for the wood to move and the concrete to be smoothed on the edges. A good test for this would be the finger test. Touch it; if your finger sinks right in, it’s too soft. Wait until your finger leaves an eight of an inch imprint, but that’s it. The whole project will take on average two full days. Due to the intensive nature of this type work, it is recommended to attain the service of a professional landscape company.
Q. What material makes the best sub-layer for concrete steps?
A. I recommend using crush and run materials (base layer). They should be placed 6-inches below the step line. If you live in northern climates where you reach below freezing throughout the winter, you will need to add a 12-inch sub base below that, making it an 18-inch base total. This is because freezing can cause what we call a heaving factor, where aggregate can move with heat and water after a hard freeze. In the 12 inches below the crush and run materials, add surge stone which is about the size of a large egg. This prevents moisture from pushing up on the product.
Q. What's the drying time before you'll be able to walk on the concrete steps?
A. Depending on the weather, you can usually walk on concrete steps within 24 hours.
Q. What other factors should be considered before building concrete steps, especially in terms of erosion prevention?
A. The condition of the soil is a determining factor. Sandy or moist soil will give, breaking the base of the concrete steps. Here in Georgia, we have red clay, so this is not an issue. Soil types in each state may vary. So checking with a local landscaper is suggested.
Q. For homeowners who decide that building concrete steps isn’t a DIY project, is there an estimated cost range homeowners should expect if a designer installs the concrete steps?
A. If a designer installs the concrete steps, homeowners should expect to pay $300 per step. I base this on an average project of 10 concrete steps for $3,000. In comparison, a stone step installation will only cost $150 per step because concrete steps are more intricate and require a higher number of team members to accomplish.
Q. Do you recommend pouring stringers for concrete steps? What are the pros and cons of including stringers?
A. No, if you use stringers for concrete steps, you cannot achieve a more consistent, monolithic pour. I recommend making boxes. The stringers are less work, but in the end, the boxes yield more of a finished look that is well worth the extra time. With boxes, you are less likely to make mistakes. Each step in the process is critical, and a professional with experience in this area can streamline the project.
David Gatti is the president / owner of P.O.P.S. Landscaping, a full-service landscaping company specializing in the creation of attractive, usable outdoor spaces.