The right staircase can dramatically improve the look of a home. Ready-made options are available from industry manufacturers. However, a straight flight of stairs is a DIY project that many homeowners can do. Plus, building a staircase from scratch may be a more budget-friendly option. Knowing how to build a staircase also allows you to customize its features. All you need are the right tools, lumber, time and help. Refer to this guide for general guidelines on how to build interior stairs.
Collect the Measurements
Understanding how to build a staircase starts by taking accurate measurements. The first measurement is the “rise.” The rise is the total distance from the floor to the top of the staircase. You can usually measure the rise using a tape measure.
Other important measurements include those of the treads, risers and stringers.
- The tread is the part of the stair you step on. The depth of a tread is from the edge to the riser. A tread’s width is the horizontal length from one side to the other.
- The riser is the vertical piece of wood or space between each tread.
- The stringers are the structures on either side of the staircase that support the treads and risers.
Tip: Include the thickness of any carpet, padding or subfloor in your rise calculations. This will help ensure the finished staircase’s treads are evenly spaced and uniform in size.
Calculate the Stair Slope
You will use your rise measurement to calculate the slope of the stairs. The stair slope is the walking angle of your finished staircase. It’s also called the “rise and run” of the stairs. A stair’s slope determines how easy or comfortable it is to walk up or down the staircase.
There are many ways to decide on the best slope for your staircase design. Here are some basic guidelines for calculating stair slope:
- For a standard slope, divide your total rise measurement by the number 7. This is the standard riser height.
- Many building codes call for stair slopes that have an angle of about 37 degrees.
Tip: Make sure the slope is in compliance with your local building codes. Check with your building permit or community affairs office for more details.
Hang the Stair Stringers
When starting the staircase construction, you’ll need to decide how the stringers will connect to the upper and lower floor. Stringers, also known as stringer board, are the outer part of the staircase housing. They keep the stairs secured on either side. Pre-cut stair stringers are available in a variety of sizes to make this part of the project a bit easier.
- Cut a notch along the bottom of each stringer for space to position it over a pressure-treated 2 x 4 cut of lumber. Methods for attaching stringers vary by local building code and your specific situation.
- Wedge the 2 x 4 between the bottom notches and secure it with wood screws.
Install the Risers and Treads
The tread is the horizontal piece that connects the stairs. The riser refers to the vertical space between steps. This space may be filled with a solid piece or be open.
- Use a circular saw to cut the risers to length of each tread.
- Secure the riser to the stringers with wood screws. Think about using a wood adhesive first for a more secure hold.
- As you install one riser, position and fasten the corresponding tread.
- Carefully climb to the next riser. Repeat until finished.
Install a Staircase Handrail (Optional)
A staircase handrail or railing is both an attractive and practical addition. You can mount a handrail to a wall or they can be integral to the design of your staircase. Depending on where you build the stairs, you may need to install stair railings to remain compliant with building codes.
Most staircases have railing or a handrail on both sides. Others may have a handrail on just one side. Very wide staircases can have a rail that is in the middle. You can build your own handrail or buy a pre-made option that fits your style.
A well-made staircase can change the look of your foyer or basement. Unlike many ready-made options, building a staircase may fit your budget better. Before you begin this DIY project, it's helpful to understand the parts of a staircase: the rise, treads, risers and the stringers. Measure accurately. Comply with your local building codes. Gather your tools and materials such as joist hangers. Ready to build your stairs? Use The Home Depot Mobile App to locate products and check inventory. We'll take you to the exact aisle and bay.