Ballasted Roof Mount vs Standard
When it comes time to choose a flat roof solution, the IronRidge ballasted roof mount system is the best & easy choice.
Composed of only three primary components, this intuitive system is easy to learn and even faster to install.
Described by a customer as “the most rugged ballasted system” he’s ever used, the structural steel framework is built to last and backed by an industry-leading 20-year warranty. Even with the heavy-duty construction, the IronRidge ballasted system is light on the roof. Through collaboration with one of the top wind tunnel testing laboratories, engineers have worked hard to develop a system that minimizes the amount of ballast required. In addition, an extruded EPDM rubber footing is available to help protect and maintain your roof’s warranty.
Modular ballasted system works with any size array and easily configures to avoid roof obstacles such as HVAC units or skylights. Since commercial rooftops are never completely flat, the ballasted solution was designed specifically with uneven surfaces in mind. The patent-pending pivoting mounting plate delivers ultimate directional flexibility allowing the system to automatically adjust to the contours of the roof.
@MickS I totally feel ya. 
I'm running into the same issues with my installer. I finally did my own research and found a ton of information on this site. I've attached a data sheet for you as well.
This diagram was super helpful to explain to my installer:
