Step by Step on How to Build a Staircase

How to Build Stairs: Materials

The following tools are the ones that you will probably need when building a new staircase in your construction project.

• Hammer
• Circular Saw
• Drill
• Chalk line
• Level
• Framing square
• PPE
• Handsaw
• Stair gauge
• 2 X 6
• 2X12
• Decking
• Screws

How to Build Stairs: Landing Zone

The first one when building new stairs is to determine where the stairs will start and where it will end. Find these two places and determine if you have enough space at both ends to be standing up safely, or at least have 24 inches available to use as the landing area. Landing space requirements are determined by local building codes, so be sure to follow your local code regulations.

How to Build Stairs: Determine Rise

Now that you have figured out the landing space available, let’s determine the rise or stair height. Measure the total rise to the landing spot with a leveled 2 x 4. Make sure that the 2 x 4 extends all the way to the place where the ground level will be, so you will have the exact measurement, measuring from the bottom part of the 2x4 to the ground level. The angle between both landings should be around 40 degrees, at a maximum. That will be the total stair rise measurement.

How to Build Stairs: Determine Number of Risers

From the previous step, use the measurement and divide it by 7 inches, minimum. The 7 inch number represents the approximate step height, which sometimes is determined or regulated by the local building code. The result number of that division is the number of required risers.

How to Build Stairs: Determine Number of Treads

Now to find the number of treads, subtract one from the number of risers, as there’s always one fewer tread than risers. Multiply the number of treads by 10.25 inches wide, or the same as two 2x6s. Measure the horizontal projected distance from the top landing to the bottom landing to be sure you are correct. Recheck all the measurements and if possible draw a simple sketch to be sure that you have the right number of treads and risers.

How to Build Stairs: Stringer

Mark on the bottom landing where the stair will actually end. Measure to determine the stringer and skirt length. Take the stringer or the 2x12 and put them on top of a sawhorse to layout the place where the riser and treads will be. Lay out the stairs by drawing on the outside of the framing square, sliding the square along until it meets the last mark. Remove ¾ in from the top of the stringer to fit the missing top riser. Mark the bottom of the stringer to remove the tread thickness. Cut the top and bottom of the stringer with a circular saw. Fit the stringer into place and check the tread level.

How to Build Stairs: Cut the Stringer

Cut along your mark making sure that you stop when you reach the corner of the notch. Finish the cut with a hand tool to prevent damaging the stringer. Use the first stringer as a pattern to cut subsequent stringers.

How to Build Stairs: Skirt Boards

Outline the pattern on the skirt board. Cut off the end of the bottom so it is about 5 inched high. Attach stringers to the skirts using deck screws placed every 8 inches, alternating fr m the front and back. If you have a middle stringer, reinforce it with additional 2x4 nailed to both sides of it.

How to Build Stairs: Attaching Stringers

Mark the left and right position of the skirts and mark horizontal lines to mark the top treads location. Tack the skirts and screw the skirts to the top landing surface. Attach a 2x6, same width of the stringer, to the back of the stringer to provide additional support.

How to Build Stairs: Add the Risers/Steps

Attach the bottom riser into each stringer and check the squareness of the stair. Nail the second riser and screw on the two 2x6 bottom treads leaving a ¼ in gap between the boards. Add all risers and treads up to the top of the stairs. The bottom riser will probably need to be cut to custom height.