2021 Stair Design Guide
Working Doc
<html><iframe src="https://docs.google.com/presentation/d/e/2PACX-1vTqRG150jtj716f1uoLq5Fc5gHi-zlIlFp9YTlpkasSmCBXdUUngxOXE3Ku27TRtt6bRj1v3bu15bSM/embed?start=false&loop=false&delayms=3000" frameborder="0" width="480" height="389" allowfullscreen="true" mozallowfullscreen="true" webkitallowfullscreen="true"></iframe></html>
CAD
Original design - File:Stairs.fcstd
Stairway for SeedHome v2
Step Size
The steps are 42.125" wide and 11.25" deep with a 1.125" nosing
Rise
<html><iframe src="https://docs.google.com/presentation/d/e/2PACX-1vRSXCc6VMyQmjkIG7K6uXMiArpF7fCctNbtMV8ujjwE0s-sc3ToOwFa0GG36xSZvTufq923kJmJzUAh/embed?start=false#36" frameborder="0" width="480" height="389" allowfullscreen="true" mozallowfullscreen="true" webkitallowfullscreen="true"></iframe></html>
The top of the 2nd story flooring is 121.375" from the top of the sill. We also need to add 1.5" from the basement slab to the sill = 122.875" total rise
The actual stairway rise will depend on the height of the landing:
With 2x6s and 3/4" planks (6.25" total) it will need to be 116.625"
With 2x8s and 3/4" planks (8" total) it will need to be 114.875"
15 steps of 7-3/4" (the maximum allowed by code) is 116.25"
15 steps of 7-5/8" provides 114.375"
The landing or the top step can be adjusted to make up the difference
CAD for Stairway with 7 3/4" rise
File:Stairs detail.fcstd - Detailed design file - 7.75" rise
File:Stairs simple.fcstd - Simple object for merge
CAD for Stairway with a 7 5/8" rise
File:7 625 stairs detail.fcstd - Detailed design file - 7.625" rise
File:7 625 stairs simple.fcstd - Simple object for merge
File:7 625 stairs example.fcstd - Example - SEH2 partial with Stairs
FreeCAD workbench to generate stairs
File:FreeCAD Stairs Workbench.zip
(Note: The generated steps need to be rotated 180 degrees for use in SEH2. If you create a simple copy, you can set the placement angle to 180 deg and then adjust the x, y, and z position to position the stairs. x=349.35" and y=186.125" should align them in the stairwell. Adjust z as needed to move them up or down to meet the landing.)