A staircase is an important structural element in any twostory building. Ladders consist of three main parts: stringers, steps and risers. Kosour is a 50x300 mm diagonal that takes the weight of people climbing the stairs. The steps are the plates that you step on. And the risers are located perpendicularly under each step. With this information, you are already ready to start building. Follow the detailed instructions below to bring your staircase project to life.
Steps
Part 1 of 3: preliminary measurements
Step 1. Measure the height of the room where you will be installing the ladder
This distance is also called the lift height. If you do not plan on making the top rung at the floor level of the room where this staircase starts, make sure to factor this into your calculations. Make sure the measurement is taken from foot to foot.
Step 2. Divide the total lift height by the standard step height
This will give you the total number of rungs for the ladder. Usually the height of the step is about 17.8 cm, but in your design the height of the steps may be different. (See below how the useful rule of thumb works.) If you have a 231cm lift, divide it by 17.8cm to get roughly 13. Adjust the step height to 13 steps.
The rule of thumb for step width and rise height is that the sum of the height and width should be in the range from 40 to 45 cm. Thus, if the rise of a step (riser) is 17.8 cm, then the step should be somewhere 23 to 28 cm. This makes the step wide enough to place your foot comfortably and normal height to climb easily
Step 3. Divide the total lift height by the number of steps to get the step height
Let's continue our example. We divide 231 cm into 13 steps and get 17, 8 cm. On the stringer, each step will rise by 17, 8 cm.
Step 4. Set the horizontal distance for each step
For each step, this distance should be at least 23 cm, but in reality at least 25 cm. Multiply the number of steps by this distance: 13 steps x 25 cm and you get 325 cm  the horizontal length of the span. This is the horizontal distance that the staircase covers from start to finish. In our theoretical example, the distance is 325 cm.
If you are planning to build a long staircase, it may be necessary to install landings. Since the longest boards that are suitable for this project may be about 5 meters, the maximum number of steps on the span will be 14. But you can arrange the site earlier if you want. If there are platforms on your staircase, treat each flight of stairs as a separate mini staircase. The steps below will help you with this
Step 5. Calculate the length of the stringer
A kosour is a board or beam that will go diagonally and will hold the steps; this is what the steps will be attached to. Determine the length of the stringer, just as we determine the length of the hypotenuse in the geometry problem:

Square the horizontal length, square the vertical, and add them together. Then find the square root of the sum.
√ (3252 + 2312) = 398.7 cm
Step 6. Determine how you will attach the ladder to the existing structures
If the staircase will rest on the vertical surface of the structure, you will only have to find a place where the stringer is directly fixed or add additional elements that will connect the structures. If the ladder does not sit on an existing support (for example, hanging the ladder), create an additional structure to support the system or modify the upper part of the stringer accordingly.
Make sure the top step is not level with the top floor. This will simplify the process
Step 7. Decide on the number of diagonal supports
To prevent sagging of the steps, a wide staircase should have a significant number of supports to evenly support the steps. For safety reasons, stringers should be located at a distance of 40 to 120 cm from each other. A very narrow staircase can do with only two stringers, but it is better to start with three and increase if necessary.
Wider stairs are almost always preferable to narrow ones. It is much easier and more convenient to move along them. If possible, choose a wide staircase and build it on three or four supports
Part 2 of 3: Making supports
Step 1. Lay down a long 2inch board (5cm x 3m
) Do not cut it to length yet; it will stand at an angle that depends on the height and depth of the steps, and the edges will need to be refined.
Step 2. Mark with a square the height and depth of the steps
In our case, 17.8cm. one side and 25 cm the other. Make sure you know exactly which side corresponds to the height of the step and which is its depth, so as not to spoil all measurements.
Step 3. Cut the top of the support at the desired angle
The angle will depend on the size of the steps. Make sure that everything is taken into account (for example, the additional length of the stringer if it will be attached below the structure with a canopy)
 Place a carpenter's square to one of the corners of the board. Mark the highest point on the board. Mark the points that represent the depth of the steps along the entire length of the board.
 Draw a line from the height point to the point that marks the depth of the step, at right angles. This will be the top horizontal line of the stairs.
 Mark on this line a value equal to the depth of the stair tread. Start at the end of the existing line, which is closer to the center of the board, measure outward and mark a dot.
 Use a square to draw a perpendicular line from the point you just placed. This line will show where the stringer will rest on what you will be attaching the ladder to.
 Cut along these lines. The top of the support will now fit at the desired angle
Step 4. Measure and mark each rung on the board
The top horizontal support line will be the reference. Measure the length equal to the height of one step, and a line indicating the depth of the step will go perpendicularly. And so on along the entire number of steps.
Step 5. Use a handheld circular saw or hacksaw to cut the steps
If you use a circular saw, use the disc to reach a certain mark, and then pick up the rest with a hacksaw or jigsaw. Stop the saw 35 mm before the perpendicular line.
Step 6. Cut the bottom of the stringer so that it sits exactly on the support
To cut a properly protruding bottom corner, simply draw a line parallel to the top cut and then saw off.
Step 7. Try on the support in place
Make sure the height is accurate.
Step 8. Use the first stringer as a reference for the next
Place the first stringer on another board and circle, and then make the necessary cuts.
Part 3 of 3: Assembling the ladder
Step 1. Install the supports
The method of connecting the stringer to the supporting structure will depend on the surfaces, the presence of a canopy, etc. One of the ways is with connecting elements. 50x300 or larger corners provide ample mounting surface. Place the support on a solid surface such as concrete, wood floor, or concrete blocks if the ladder rises from the ground.
If installing on concrete, place roofing material so that the wood does not get damp and does not collapse
Step 2. Secure the stringers by sewing the openings between the steps (optional)
They are usually sewn up with inch boards. While you can do without it, attaching the vertical planks between the treads will make the ladder look better, be more durable, and will cover rough cuts in the stringer.
Step 3. Cut and install the risers
Cut the material to length and secure to each stringer with 6 cm screws.
Step 4. Cut and install the steps
Cut the material to length and secure with 6 cm screws. If desired, do so that the boards of the steps slightly go beyond the kosour.
For beauty, determine the required depth of each step (plus the ledge), divide by two, and cut each board to this width; then you can make a step from two boards
Step 5. Fit each finishing board to the overhang and nail to the vertical board
If you want to add more class to your staircase, you can install finishing boards cut to the length of the step and fix them from below.
Step 6. If necessary, cover the stairs with varnish or paint
Protecting the staircase from rain and sun is especially important when it is outside. Even if you are building an indoor staircase, consider protecting it from everyday wear and tear.
Advice
 Remember that indoor staircases require higher quality materials and must be extremely precise.
 Using a pair of levels on a carpenter's square guarantees accuracy.