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The right staircase can dramatically improve the look of a home. Ready-made staircase options are available from industry manufacturers. However, building 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. Building your own staircase also allows you to customize its features.
This guide will show you how to build a staircase inside your home.
Know the Parts of a Staircase
As you learn how to build a staircase, get familiar with these basics:
- The distance from the floor to the top of the staircase.
- In this illustration, the total rise is 45 and 7/8 inches.
B: Top Step
- The top step can be slightly shorter than the other steps if the rise can’t be divided evenly.
- It should be no more than 3/8 inches shorter than the bottom step.
C: Total Run
- The total run of a staircase is the total number of treads multiplied by the depth of the tread. You then add the nosing and riser thickness to get the total run.
- The run in this illustration is 60 inches.
- The total run has to be less than the total distance available where the staircase can be built.
The minimum clearance for a staircase is 6 to 8 feet overhead.
- The part of the stair you step on.
- The tread is usually at least 10 inches if the stairs have nosing. The tread is typically 11 inches if the stairs don't have nosing.
- There should be no more than 3/8 inch of variance in depth between the bottom and the top tread.
- The typical minimum tread depth is 10.
- The boards used for the tread are usually 1 inch thick.
- The part of the tread that sticks out over the riser.
- Each nosing typically overhangs the stair below by 3/4 inch to 1 1/4 inches.
- The vertical piece of wood between each tread.
- In this illustration, the risers for the middle steps are 7 1/2 inches. The riser for the top step is 7 3/8 inches. The riser for the bottom step is 7 3/4 inches.
H: Maximum Overall Rise of Step
- The rise of a single step should not be more than 7 3/4 inches.
- If the total rise for the staircase doesn’t divide evenly by the number of steps, you can make up the difference with a slightly taller bottom step.
- The rise of the bottom step should not exceed the maximum riser height. It should also not be more than 3/8 inches taller or shorter than the top step.
Stringers (not pictured): The structures that support the treads and risers. Stringers are located on each side of the staircase and in the middle of it.
Note: Check your local building codes for requirements in your area before building a staircase.
As you figure out how to build a staircase, you need accurate measurements. Get someone to help you measure everything. Working with another person will help you get the most accurate dimensions possible.
If you have to make measurements alone, use a reliable laser measure.
The first thing to measure is the “rise” of the staircase. 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. 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.
Other important measurements are:
- The tread’s depth and width. The depth of a tread is from the edge to the riser. The tread’s width is the horizontal length from one side to the other.
- The riser, which is the vertical piece of wood or space between each tread.
- You’ll need to figure out the number of stringers your staircase requires. Typically, a stringer is required every 18 inches. Staircases are usually a minimum width of 36 inches, not including the handrails. A 36-inch-wide staircase would require three stringers. There would be one on each side and one in the middle of the staircase.
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.
- Make sure the slope is in compliance with your local building codes. Check with your building permit or community affairs office for more details.
It's important to note that building codes allow for a variance, usually the bottom step (or both the top and bottom step), in case the math does not work out as an even number for all the risers. Also, building codes have a minimum and maximum rise dimensions for treads. Be sure to check local code for minimum/maximum measurement requirements as they relate to risers and treads. When the riser dimensions can't all be the same, this variance will need to be accounted for.
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.
If not using joining plate hardware, a notch can be cut in the top of the stringers and laid across a ledger mounted to the face of the landing where the stairs terminate at the top.
Tip: If you prefer to make your own stair stringers, use a carpenter square or stair gauges. Cut notches out of the frame and cut out the shape. You can use a circular saw to do this.
Install the Risers and Treads
Again, 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 and width, if applicable, of each tread.
- Secure the riser to the stringers with wood screws. Start at the bottom and work to the top.
- Using a construction adhesive to secure the treads and risers is good idea. It will provide a more secure hold. The adhesive will also help prevent squeaking in the future, as the stair assembly settles into usage.
- 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. 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 one that fits the style of your staircase.
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.
When there are walls on both sides of the staircase, mounting handrails will be fairly simple. Creating a railing that is part of the design of the staircase is a more complex endeavor.
A staircase is usually at least 36 inches wide, which does not include the handrails. There should be at least 36 inches between handrails on either side of the staircase. Posts are typically bedded into the ground to support the rails.
When building a staircase, check the local building codes. There may be requirements for handrail heights and how to anchor the rails.
A well-made staircase can change the look of your foyer or basement. While ready-made staircase options are available, building your own stairs may fit your budget better. Before you begin this DIY project, it’s helpful to understand the parts of a staircase. You’ll need accurate measurements. You’ll also have to comply with the building codes in your area.
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