Soil type and clay

I’ve been using this post to determine soil type I have:

The issue is by using web soil survey I get “Sandy loam” with 0.11 available water. However at around 8 inches I have clay layer which would obviously block water runoff. How do I make rachio account it?

Another question is about root depth, I’m in Seattle area, so I chose cold season grass, which set my root depth to 6 inches, however I doubt it is. While moving some sprinklers around I noticed that the maximum depth is around 2-3 inches. Can it be true or am I missing something?

If you are watering only grass, and the impermeable clay layer is at 8 inches, you likely don‘t need to worry about it, since your cool season grass will likely not root much deeper than 6 inches. The controller will try to water only for the root depth you set. In your soil, grass should be growing its roots deeper than 2-3 inches — it may be that it was never watered deeply enough. Try setting the zone to what you found (0.11 available water) and keep the defaults (unless of course you know/tested the precipitation rate of your sprinklers, then set that differently). See how the grass and soil reacts, adjust as necessary. It‘ll take a bit of time and effort to get Flex dialed in but worth it once done.