I used heavy stainless lag bolts (4 inch length) screwed into the stair
frame (stringer), where it meets the concrete. The pointee part of the
lag bolt points skyward, the head side rests on the concrete slab. I
used two lag bolts on each stringer.
I left the bolts protruding about 1 inch. The heads of the lag bolts
sit on the concrete slab.
After assembling the stairs and bolting them to my patio, I adjusted the
hex head lag bolts using an open end wrench, to compensate for any
irregularities in the concrete slab. This prevents the stairs from
"rocking" because one or the other stringer isn't sitting exactly on the
slab.

The advantages to me are.
1. As / if, the slab settles, I can adjust the bolts to compensate for
the new "gap".
2. I have air flow under the wood stair support (stringer) so that any
water will dry up faster.
3. The stainless lag bolts won't be a problem in my future.

In my part of the world, rain is a very big part of life. I feel that
anything that holds water, such as the joint between anything exposed
to water, is a problem in the making.



Ben Gold wrote:
Eventually I'm going to build a simple staircase out one of my back
windows into my yard * currently I have to go to the basement to get to
the yard.

The staircase will rest on metal and concrete, which is a bad thing, no?

Wondering if there's any techniques people use to space wood from
concrete/metal? I'm imagining tough plastic or wood "dowels" that would
work as spacers, or strips of rubber or plastic.

Any ideas appreciated.

-Ben