Bela Abolfathi, D. S. Aguado, Gabriela Aguilar, Carlos Allende Prieto, Andres Almeida, Tonima Tasnim Ananna, Friedrich Anders, Scott F. Anderson, Brett H. Andrews, Borja Anguiano, Alfonso Aragon-Salamanca, Maria Argudo-Fernandez, Eric Armengaud, Metin Ata, Eric Aubourg, Vladimir Avila-Reese, Carles Badenes, Stephen Bailey, Christophe Balland, Kathleen A. Barger, et al (328)
Stair Stringers (7) Stair stringers form the backbone of a set of stairs. By code, stairs need to be at least 36 wide. Although it's usually possible to get away with just using two stringers, we recommend you add a third one down the middle. This extra stringer will ensure your stairs are exceptionally rigid.
The following analysis demonstrates results of a typical wood-framed stair stringer configuration as well as several similar configurations. Consider 15 risers at 7Â¼-inch tall with 10Â½-inch wide treads and stringers cut from SPF No. 1/No. 2 2x12s. This configuration results in an effective throat depth of approximately 5 inches for a horizontal span of 12 feet and 3 inches.