Wawrecker, I have seen contracts for retainage up to 15% before. I have also seen, where the GC can withhold up to a specific %, and thier C withhold from thier SC, until it cant stretch no more.
We will be starting a T & M job next month, we were very specific to our needs on our contract, and NO retainage, however, they did cut some of my equipment rates and cost plus 5%.