How to Design Log Staircases

Gather drafting paper and a calculator to manually draft the log staircase design plan. You may also purchase CAD (computer aided design) software or an online design tool to draft the design plan.

Decide if you would like the staircase design to be straight, spiral or winding. Straight staircases have an inherent simplicity and tradition. Or, step away from the traditional with a winding or spiral log staircase. Spiral staircases are ideal for houses where a normal straight construction does not fit.

Start drafting the placement of the staircase, then calculate the required design of the stairs based on the space and placement.

Consider the structural support of the house in the draft to be sure it can support the design. Spiral log staircases, for example, require a very strong structural support as they are a heavy load. Spiral staircases consist of center posts, log treads and the handrail, which may also be made of logs. The center post must be cut from an extra wide (in diameter) log to allow the necessary support for the weight of the stairs, and the weight of the people using it.

Determine the rise of each step on the staircase. Consult local building codes to determine the ideal and legal measurements for the risers. For a home with three stories or less, the risers typically should measure about 7-3/4 inches in height, according to the International Residential Code.

Use a calculator to divide the total height span of the staircase by the height of the riser to determine the number of steps necessary. Staircases spanning 7 feet with 6-inch risers will yield a total of 14 steps. Measure, draw and mark on the draft paper or computer software.

Determine the thickness of the log steps. The thickness of the tread should be included in the total riser height. Building inspectors include the thickness of the tread in the total riser measurement. Draft the thickness of the log in the design plan.

Determine the depth of each log tread. Consult local building codes for specific requirements. The required depth typically is 10 inches, according to the International Residential Code. Measure and mark tread depth and the overhang on the computer drafting software or drafting paper.

Calculate the tread width. It is normally a minimum of 36 inches, but consult local building codes.

Draft other features, such as the handrails, and always consult the local building codes for specific requirements.