Firstly, you need to decide on wood and its preparation. An important parameter is its humidity, it should be within 8-12%, which should be reflected in the quality certificate. It is better to make a design from solid wood bars – so it will be more reliable. When harvesting, take larger bars than you need, since later surpluses will come down during processing, and over time the tree dries. Also at the ends of the bars there may be cracks or a knot. If you have to tighten screws into knots, this will reduce the strength of the structure, so it is important. Next, you need to decide on tools. We advise you to pay attention to wood saw saws. When choosing, be guided by such characteristics as the maximum height and saw width. For the manufacture of the stairs, saws with a maximum height of a 90 mm and with a width are suitable – more than 300 mm. Next follows the calculation of the stairs. The main principle of calculation is the maximum convenience and safety of moving along it. A gentle and wide staircase is the most convenient, but in each individual case the decision may turn out to be different. The main parameters of the stairs: type, height, area, steepness, number of steps. Among these parameters there is some dependence, for example, the area and height of the rise determine the steepness. Safety and convenience. These words mean the width of the steps, it should be such that they can easily move along them without sensing. The minimum recommended step width is 90 cm. If the ladder is already these borders, then it will be difficult to carry overalls on it, especially if it is a twisted staircase. Then you need to calculate the slope. It should be a length in the human step, t. e. a certain ratio between advancement up and advance forward must be observed.