What Is Staircase Stringer?
Staircase stringers are small inclined wooden boards which provide support to the steps. They are generally 4-5 cm thick and 25 – 40 cm deep.
Stringers are supported on newels, trimming joists, or pitching pieces. The staircase strings or stair stringers are mainly three types cut stringers, closed stringers, and mono stringers.
Types Of Stair Stringer:
- Cut Stringers
- Closed Stringers
- Mono stringers
1. Cut Stringer
The treads are visible from the side, overlapping the stringer by 25 mm. Cut stringer improves the appearance of stair but weakens the stringer due to deep cut in it.
2. Closed Stringer
Closed stringer is also known as housed or routed stringer. They consist of grooves to insert the ends of the steps inside of the string. Closed stringers have top and bottom edges parallel to the pitch of the stair.
The stair treads and risers are strongly secured to the stringer by nailing, gluing, or wedging. However, the treads are not visible from the side.
3. Mono Stringer
In this type, the center of the treads is supported on a single ‘beam-like’ stringer from below. There are no risers present are in mono stringer stairs. Due to this structural feature, they have modern and appealing looks.
This minimalist style offers open space, a wonderful flow of light, and the feel of floating stairs. If you want to install a modern stair, then the mono stringer is a trending option to consider.
Procedure To Cut Stair Stringer:
Stair Stringer Calculation:
1. Calculate Tread and Riser:
First, measure the required height of the stair using a tape (assuming 63 inches).
Now you need to know the height of riser. The standard height of riser of a step is about 7 inches (18 cm) which can vary little bit.
2. Calculate Number Of Steps:
Divide the overall height by the riser height to get the number of stairs.
No. of steps = 63/7 = 9
3. Calculate Run Of Stair:
To calculate the run of the stairs, multiply the number of steps with the desired width of the tread.
The building code suggests each stair run should be about 10 inches (25 cm) to fit people’s feet comfortably.
Run of the stair = No. of steps x width of tread
= 9 x 10 = 90 inches
4. Calculate Inclined Length Of Stair:
Once you have the overall rise and run of the stairs, you can calculate the inclined length of the stair. Inclined length is also required for making stair stringer.
To calculate this we will use Pythagorean theorem which is a2 + b2 = c2
- a = 63 inches
- b = 90 inches
- c =?
- c2 = 63² + 90²
- c = 110 inches
5. Marking of Tread and Riser on the Board:
Pace a framing square near the end of a 2 x 12 (38 x 286 mm) wooden plank board, and mark the tread and riser dimension on it. Make sure you leave few inches at the end before the end of the square.
Cutting Of Stringer:
Cut down the marked lines on the stringer using a circular saw. Leave about 0.5 inches (1.3 cm) of the line uncut, which you will finish with a hand saw. Take proper precautions before using the circular saw.
Trim the top and bottom of the stair stringer. Cut the top of the stringer along the first rise line. Then trim the bottom run line, that was already marked to make it shorter than the others by an amount equal to the tread thickness of your stairs.
Use the first stringer as a template to cut the subsequent stringers for your stair.