I'm posting this for my dad, who does not have Internet capability:
When the builder laid the concrete slab for our front porch, he failed to put in proper footings down to hardpack. Although we cannot see it, we think he drilled into the bottom of the floor trusses to anchor the r-bars. This was on top of the concrete house foundation. Consequently, the slab started to settle and cracked crosswise. The builder left town with no forwarding address. We had someone else put in additional footings at the front edge. Now the whole slab is settling and leaving a one-half inch crack near the foundation, which is increasing in size.
We solicit your ideas on how this can be corrected. My wife and I are in our 80s and appreciate all the help we can get.