steeda wrote:
Hello,

I just bought a house in Santee, CA, known for expansive soils. After

pulling up some carpet, I found 2 hariline 1/16" cracks running
across one
of the rooms. ( an addon, which was to code ). The house is 30 years
old,
the addon is 8 years old. I haven't pulled carpet from the original
structure yet. The largest width mesaured at any point in the cracks
is
1/16". The crack "splits apart' and the sides are totally level with
one
over, not an up/down situation.

Is this a concern?

ALL concrete can, and will, crack. That's why they put wire or rebar
imbedded in the concrete - so that when it does crack it won't cause
problems.
Bob S.