Another method I've used in the past, is to set a 20 ft pole right next to the house in concrete, then attach it to the house or rafter tails with unistrut and clamp. I'll usually use a 4 ft piece to spread the load out over at least three structural members. Then the pole extends 4 to 6 ft above the roof as necessary to clear the roof with the bottom array edge. This allows you to set what ever tilt and azimuth you want independent of the roof orientation. 2nd, it keeps you from making any penetrations on a sketchy roof 3rd it gets the array up higher for theft and shade prevention. 4th it allows seasonal tilt adjustment, and its fairly easy to install the modules from the roof, as you just rotate the rack over the roof to install, then rotate back out after. I've used it in several systems, that have been up for over 10 years. With grid tie and cheap modules, I quit using this method, but it might be just the ticket. Russ has done these before, too.
Ray On Mar 25, 2012, at 9:21 AM, William Miller wrote: > Allan: > > We recommend the custom, top-of-pole roof-mount: > http://millersolar.com/MillerSolar/Portfolio/pole_mount/Custom_tracker_moutn_on_power_shed.jpg > > Just kidding! (A customer rigged this up. Scary...). > > We have used the DPW TTRGM racks on flat roofs. We have a few of them tilted > up on pitched roofs, but I avoid lifting them because of aesthetics and wind > loading. If this is an off-grid, adjustability or at least a higher tilt > angle is necessary, so this rack would suffice. It does require at least two > people, preferably three, to adjust. > > We build them with the legs set to high and then lower them all of the way, > or part way, depending on the design. Some new modules do not have flanges > in the back for through-bolting, these would not work. > > We have also used various brands of extruded rail with legs to tilt them up. > See attached photo. These get flimsy so I stay away from them. > > Good luck. > > William Miller > > > At 07:19 AM 3/24/2012, Drake wrote: >> Allan, >> >> I haven't had any off grid, adjustable roof mount systems in years, but have >> one coming up. What is the best product these days? >> >> Thanks, >> >> Drake > <Back_of_racks.jpg>_______________________________________________ > List sponsored by Home Power magazine > > List Address: [email protected] > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
