Retainage is a necessary evil with so many subs doing poor to downright unprofessional work. The whole deal is tracking it and having enough resources to back it up every week. Just like QC'ing, it takes time, effort, and organized paperwork to handle it properly. And you will still have one side saying he is right.
What I changed to was a two week payperiod with payroll 12 days out from the end of week 2. No retainage and backcharges dealt with every week so everyone knows what to expect. When most subs first started they got hot, but after a while they saw we were consistent, and the quality of work went up. Every now and then you hit a grey area and we settle it as professionaly as possible.
The bottom line is everything has to be dealt with in real time, open communication must be kept, and there must be resources provided from the contractor side to deal with it.
Anyone thinking that a contractor makes out with backcharges is mistaken. You have alot of wasted time tracking backcharges, writing up paperwork and qc's, going through payroll double checking that the charges were applied correctly, dealing with tech's swearing that they did the job right (even after showing them qc pictures within 2 days of the install), and potentially losing your contract because your qc quota isn't where they should be because of time spent with troubled techs.
Ask any contractor how nice it would be to just pay a qulaity person a quality wage to do a quality job. Everyone would just focus on the work at hand and take care of the customers. You would have minimal customer complaints, no damage claims, no on-time guarantees, and perfect pay every two weeks without a hickup. Sound too good to be true! Everyone do your best and treat each other like you want to be treated. Be professional (both contractor & sub) and take care of the CUSTOMER, after all without them we all do not have a job. Peace to everyone and god bless the good people with good Karma!! AMEN