Ballasted Solar PV Mounting System for Flat Roof – Part I

SBS Solar is very excited to begin installation this week on what is one of our largest residential solar systems, to date.  Most of our customers go with a 2kW-4kW system.  This one is a whopping 8.6kW – that is 36-panels at 240w per panel.


A ballasted solar PV mount is a graceful, highly engineered solution that secures the array without damaging the flat roof. It is compatible with the usual framed photovoltaic modules and typically does not require roof penetrations. Made from lightweight and strong aluminum construction, this Uni-rack Rapid Rack G-10 system is at a 10-degree tilt and will look pretty sweet when it’s done.


Right now our team is setting up the base of the system, which includes the ballast block trays which each have a 4″x8″x16″, 26-pound cement  block in each tray.  There are 5.5 blocks per panel, to keep it properly weighted down.


In these photos you can see the 30# strips of 36″ wide tar paper below the blocks, trays, and ballast frames.  You’ll notice that there are rocks on the roof.  This is to protect the EDPM membrane.


In our next post, we’ll start to show the racking and panel installation.  In the final post, expect pictures of the finished system.



3 replies on “Ballasted Solar PV Mounting System for Flat Roof – Part I”

  1. […] We have finished our ballasted roof project from earlier this summer. (This is continuation of Ballasted Part I.) […]

  2. We’ve been told by two different companies here in Hawaii, that they can’t put pv panels on our house because the roof is a flat tar-papered with open beam ceiling and no attic. Our house was built in the 1960’s. We have three solar water heating panels on the roof. It sounds like you have found a solution for this problem. Do you have a distributor in Hawaii?

  3. mbradford says:

    we do not have a distributor in Hawaii. But we can certainly look into this for you.

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