While not new, since the concept was already described by Christopher Alexander in its architectural theories, it only gathered some traction in programming due to the publication of Design Patterns: Elements of Reusable Object-Oriented Software book in October 1994 by Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides, known as the Gang of Four (GoF), that identifies and describes 23 classic software design patterns.
Use a calculator to calculate the stair riser length or the number of steps you'll need. Divide the height from the first floor to the top of the second floor by a predetermined height of your choice for the riser. The typical height of a riser is 6 or 7 inches (15 to 17.5 cm).
* Stair Tread Styles. All standard stair treads are 11 Â½ deep X 1 thick X (length specified). Acceptable tolerances are +/- 1/32 on depth and 1/64 on thickness. Tread ends are not end cut and average Â½ â1/8 over finished size to allow custom fitting in the field. Stair-Treads.com also end seals every board used to manufacture our treads.