How To Layout Bottom of Stringer With Building Hardware
When you're looking at here is a 4 x 12 stair stringer that is sitting directly on top of a 1 inch standoff base plate that's commonly used for patio cover posts.
What I like to do is place the finished stair stringer
into its proper position, without nailing it. This isn't going to be
easy to do and might require additional workers or in some cases, a
crane to lift these heavy objects.
Then you can place the hardware or base plate underneath the stair stringer and mark its exact location. Once the location of the base plate has been marked, you can remove the stair stringer and fasten the base plate securely to the concrete foundation.
Now you're probably wondering why in the world would you want to go through all of this trouble, when you can simply set the stair stringer directly on top of the concrete foundation.
The raised base plate will prevent any moisture in the concrete slab or around this area, from absorbing into and eventually destroying the wood stringer.
There are other things you can use to separate the wood from the concrete. This is only one method, but it's one I've had great success with.