None, I am an EE not CE, even though I worked for the CE department when I was in school. My thought is when you have the guy who writes the books about structural failure in slabs right here in town and he does consulting at very reasonable rates why would you use any one else to evaluate slab issues. I have referred him to many over the years, some for initial build, some for design verification and some for problem resolution. Everyone I referred thanked me for the recommendation. When he designs a slab he shows up to inspect the site and verifies that the soil is prepared as directed and that all the strength members are built, tied/welded as per the specs. He does not assume things and have seen him measure and make them reset forms so its square not the trapezoid they formed. He probably does not even remember me, and he has plenty to do and is not out looking for extra work. He is just the right guy for the job.
I am sure Gessner and others are fine engineers, especially if they have studied and learned from Skip's research in the area.
[This message has been edited by UmustBKidding (edited 7/23/2013 10:34p).]