In building a set of wooden stairs it is important to understand the terminology of stair case building. Here is a quick over view of the common terms used in stair case building and plans.
Total Run – The horizontal distance the stair case covers.
Total Rise – The vertical distance the stair case covers from the surface of the landing to the surface of the upper floor.
Run – Is the horizontal distance from the leading edge of one tread to the leading edge of the next tread. Eleven inches provides an ideal run or thread width.
Rise – Is the vertical distance from the top of one tread to the top of the next tread. 7 1/4 inches provides an ideal rise or step height.
Passage width – Is the width of the stair case. The minimum width for a stair case is thirty six inches. Forty eight inches is ideal for one person. Sixty inches provides ample space for two people to use the stair case in unison.
Slope – Is the degree of elevation of the stair case. As a rule the stair case slope should be between thirty and thirty five degrees.
Stringers – Are the sloped boards that support the stair way. 2 x 12’s are standard lumber used for stringers. However, with the advances in engineered lumber LVL offers significant structural and load bearing improvements over dimensional stick lumber. Consider using 1 3/4 LVL for the stringers of your stair case.
Stringers should be spaced no further than twenty four inches apart when using 1 1/2 thick lumber for the treads. Adding an extra stringer will provide a stiffer and sturdier stair case and is well worth the additional cost.
Threads – Are the horizontal boards that you will be walking on to traverse the stair case. 2 by stock will provide a solid stepping surface for your stair case.
Risers – Is the vertical end of the back of each tread. 3/4 inch material is ideal for covering the riser. You can use solid wood, plywood, or OSB as the riser.
The next installment will have the cutting out and assembling of the stair case.
