How to Build Porch Stairs

Front porch steps.
Even basic porch stairs like these take precise planning and careful construction. McBride

­You have the perfect porch you've always wanted. It's sturdy with a nice railing and a wooden swing, but it's still missing something. You need a way to get off that nice porch and onto the ground -- you've got to build porch stairs.

Building stairs is a very difficult job, even if it's just a short porch staircase that might be only a few steps high. Though you can surely do it on your own with lots of careful planning and design, you should build porch stairs -- or any stairs, for that matter -- on your own only if you have carpentry experience and feel comfortable with the job. As with any building work, be sure to check the local codes and obtain any necessary building permits.­


­In this article, we'll learn how to build porch stairs, starting with the most important step -- designing them. You might think, they're stairs -- what is there to design? But this is the most crucial aspect of the project. The design of the stairs is so important that some carpenters buy drafting software for this step. The actual construction isn't particularly difficult -- it's the preci­se measurements and calculations that can trip you up. If math isn't your strong point, you might want to save this project for a professional. If you're willing to put in the proper planning, however, building your porch stairs shouldn't be too hard.

So, haul out your measuring tape and calculator and try to remember high school geometry class as you head over to the next page.


Designing Porch Stairs

­We've all been frustrated by poorly designed staircases. Steep, narrow basement steps make everyone ­ nervous. Or maybe you've been annoyed by excessively squat and wide marble steps in historic ­ buildings. Attempting to fit a staircase into too small or too long an area can result in stairs that feel awkward to use. That's something you definitely want to avoid with your homemade stairs. Fortunately, a porch stairs project doesn't cause so many headaches -- you should be able to build them out to the proper place, instead of having to fudge the numbers so a basement connects to the ground floor.

Designing a staircase isn't about scallops and flourishes on the railings. It's about figuring out the correct number of stairs.


To design your stairs, follow these steps:

  1. Measure the rise of your future staircase in inches (or centimeters) and divide by 7 inches (18 cm), the ideal step height, to find the number of steps.
  2. Divide your porch height (or total rise) by your number of steps to find out how high each riser should be. Round to the nearest quarter inch (quarter centimeter).
  3. The rise height determines the run width. Find a chart like the one here to determine your run width based on your step height [source: DoItYourself].

If you made it through all that math and your head's still on straight, then step on over to the fun stuff -- the actual building of the porch stairs.


Building Porch Stairs

­Now that the hard part is out of the way, yo­u can move on to what you came for -- the construction of the porch stairs.

Got your steps designed? Check. Got your local building codes? Check. Got all of the necessary permits? Check. Then you'­re ready to go with the following basic steps:


  1. Position the stringers based on your measurements. (Stringers are the cutout boards on which your steps will rest.)
  2. Attach the stringers with lag screws (heavy wood screws with square heads).
  3. Cut the risers based on your calculations and screw them in.
  4. Install the treads, screwing them in both at the ends and down the middle [source: Hazelton].

Most likely, you'll want a railing so you can grip something when walking up and down your beautifully constructed stairs. To do so, first install a post before you install the lowest tread. (Be prepared to cut the tread so that it fits around the post.) Then, install the railing. This can be as simple as a piece of lumber connected from the post to the top of your porch, though you may want to have it both at the top of the post and then reinforce it by putting another one closer to the steps.

It might not be the easiest carpentry job you've attempted, but by using a little foresight, you can build a great set of porch stairs in just one weekend. Now get your measuring tape and your hard hat and get going. For more information, visit the links on the next page.


Lots More Information

Related HowStuffWorks Articles


  • Adams, Doug. "How to Build Stairs." Extreme How To. (Accessed 12/16/08)
  • DoItYourself. "How to Build Outdoor Stairs." (Accessed 12/16/08)
  • Hazelton, Ron. "How to Build a Porch Stairway." Ron Hazelton's HouseCalls. (Accessed 12/16/08)
  • Maki, Bruce W. "Designing Stairs and Laying Out Stair Stringers." HammerZone. (Accessed 12/16/08)
  • Truini, Joseph. "How to Build Stairs." Popular Mechanics. October 2007. (Accessed 12/16/08)
  • YouRepair. "HowTo - Building Wood Porch Stairs." May 5, 2008. (Accessed 12/16/08)