How to Build Stairs Off a Deck: A DIY Step-by-Step Guide

Are you looking to add some functionality and flair to your outdoor living space? Building stairs off your deck is the perfect way to level up your backyard game. Not only does it make accessing different parts of your yard more convenient, but it also adds an aesthetically pleasing touch! In this blog post, we’ll walk you through the process of building deck stairs from scratch. Don’t worry; even if you’re new to the world of DIY projects, this guide will help you get started on the right foot (or step). So grab your tools and let’s dive into this exciting home improvement project!

Materials & Tools You’ll Need

Before we start building, let’s gather all the necessary materials and tools. Here’s what you’ll need:


  • Pressure-treated lumber (2x12s for stringers, 2x6s for treads, 4x4s for posts)
  • Decking screws
  • Galvanized nails or structural screws
  • Concrete mix
  • Gravel
  • Ledger board (if attaching stairs directly to the deck)


  • Circular saw
  • Jigsaw or handsaw
  • Tape measure
  • Level
  • Square
  • Hammer or drill/driver with appropriate bits
  • Post hole digger or auger bit attachment for a drill/driver -Stair gauges (optional but helpful)

Step 1: Determine Your Stair Measurements

The first thing we need to do is figure out our stair measurements – specifically, the rise and run.

Rise: This is the vertical distance between each step. To determine this measurement:

  1. Measure the height from ground level to where you want your stairs to end at your deck.
  2. Divide that number by how many steps you want in total.

For example, if you have a 35-inch height from the ground to the deck and you want seven steps, your rise would be 5 inches (35 ÷ 7 = 5).

Run: This is the horizontal distance between each step. The standard run is about 10 inches per step.

Now that we have our measurements, we can move on to building our stringers – the backbone of our stairs!

Step 2: Cut Your Stringers

Stringers are essential for supporting your stair treads and maintaining a sturdy structure. To create them:

  1. Take one of your 2×12 pressure-treated lumber pieces and mark out where each tread will go by measuring the rise and running along the edge.
  2. Use a square to ensure accurate angles.
  3. If desired, use stair gauges attached to your square to make marking easier.
  4. Once all treads are marked out, cut along these lines with your circular saw or jigsaw/handsaw combo.

Note: You’ll need at least three stringers for a standard set of stairs (one on each side and one in the center). However, wider stairs may require more stringers for added support.

Step 3: Attach Your Stringers

There are two ways to attach your stringers – either directly to your deck using a ledger board or by installing posts at ground level.

Option A: Ledger Board

  1. Securely attach a pressure-treated ledger board along the edge of your deck where you want your stairs.
  2. Position one stringer at either end of the ledger board so that it’s flush with both edges; secure it using galvanized nails or structural screws.
  3. Install any remaining stringers evenly spaced across this length; secure them as well.

Option B: Posts & Concrete

  1. Dig holes at least three feet deep (depending on local code requirements) where your stringers will meet the ground. Space them according to your desired stair width.
  2. Fill the bottom of each hole with a few inches of gravel.
  3. Mix and pour concrete into each hole, ensuring it reaches above ground level but doesn’t touch the wood.
  4. Insert a 4×4 post vertically into each hole (ensuring they’re level), then brace them while the concrete sets – this may take up to 48 hours.
  5. Once set, trim your posts to match the height of where your stringers will connect.
  6. Secure your stringers using galvanized nails or structural screws.

Step 4: Install Your Treads

Now that our stringers are in place, it’s time to install our treads:

  1. Cut your 2×6 pressure-treated lumber pieces to match the width of your stairs (allowing for overhang if desired).
  2. Starting at the bottom step, position one tread on top of your stringers; ensure it’s square and flush with all edges.
  3. Securely fasten this tread using decking screws through the top and into each underlying stringer.
  4. Repeat steps 2-3 for the remaining treads.

Tip: If you want an overhang on both sides of your stairs, use a jigsaw or handsaw to create notches around any outer posts before installing these treads.

Step 5: Add Optional Handrails & Finishing Touches

To enhance safety and style even further, consider adding handrails or other finishing touches such as:

  • Installing balusters between handrail posts
  • Staining or painting wood for added protection and aesthetic appeal
  • Adding deck lighting for nighttime visibility

How To Build Stairs Off A Deck Conclusion

And there you have it! You’ve successfully built sturdy and stylish deck stairs that’ll elevate both form and function in your outdoor living space.

By following these steps, you can ensure that your stairs will be safe and secure for years to come. First, plan out your project carefully by measuring the height of the deck and determining how many steps you need. Second, purchase materials that meet local building codes and are strong enough to withstand outdoor elements. Third, take time to prepare the area where your stairs will be installed – make sure it is level and free from debris. Finally, build your stairway according to instructions with quality craftsmanship for a sturdy result. With these tips in mind, you’ll have no trouble building safe and beautiful stairs off of your deck.

Remember always to follow local building codes when constructing any home improvement project, and don’t hesitate to consult with a professional if you’re unsure about any aspect of the process. Happy building!