How to Measure for a Straight Flight of Stairs

When you are building a set of stairs, you must know how to measure the stairs for the amount of wood you need for your stair stringers. Your stringers are what your steps actually attach to. These are normally cut out of 2-by-12s or 2-by-10s.

Difficulty: Moderately Easy

Instructions

1. Measure from the top of your landing, straight down to your floor. For example, if the landing is on the second floor, measure down to your main floor by bringing your tape measure straight down in a vertical position.

2. Take the measurement from Step 1 that may be 96 inches from the landing straight down to the main floor as an example. A standard rise on a step is 7 inches. So, divide 96 by 7 inches. This gives you the number of steps you need--approximately 14 steps when you measure for straight stairs.

3. Consider the 14 steps it takes to reach the bottom of your main floor when you measure for straight stairs. You must cut these 14 steps out of a 12-foot length, 2-by-12 or 2-by-10. If you use a 2-by-10, you need 2-by-4s 12 feet long to support your step treads on the 2-by-10. The reason for this: using 2-by-10s when cutting a 7-inch rise in a 10-inch step takes the "meat" out of the back of your 2-by-10. The 2-by-4s stiffen the 2-by-10s, so they won't have spring in the step.

4. Buy three 12-feet 2-by-10s or 2-by-12s for your straight stairs: one outer, one inner and one middle when you measure for a straight flight of stairs.