| Solar Guppy Discussion Forum http://solar-guppy.com/forum/ |
|
| A question about roof mounting http://solar-guppy.com/forum/viewtopic.php?f=4&t=722 |
Page 1 of 1 |
| Author: | sub3marathonman [ Mon Dec 08, 2008 10:49 am GMT EthGMT ] |
| Post subject: | A question about roof mounting |
Things are progressing once again, since the "t-feet" for the mounting brackets have arrived finally. But that now raises the question about the best way to install them. At first the roofer wanted to just bolt them down through the shingles into the rafters with the lag screws and sealant on the "t-foot" to keep things watertight. I said that sounded a bit questionable, and he said that the sealant would have to be redone probably every five years if not sooner. I then suggested mounting the "t-foot" under the shingle, with the lag screw into the rafter and sealant on the "t-foot" and then cutting a hole in the shingle for the vertical part to stick up through, with sealant on the shingle then to help keep things watertight. He said that would last the life of the roof. He said the shingles would also eventually conform to the shape of the foot after they are heated in the summer, which would also help keep things watertight. I'm not sure how much of that would happen though, to me the shingles seem pretty stiff. I am wondering what some of the experts here think, and what people have already done. Also, I'm wondering if flashing should be installed under each of these "t-feet" or if there is something in the roofing code that required it. Any help is greatly appreciated. |
|
| Author: | solartek [ Mon Dec 08, 2008 2:31 pm GMT EthGMT ] |
| Post subject: | Re: A question about roof mounting |
Not sure what you mean by "t-feet". For composition shingle roofs I have used the Quickmount PV product http://www.quickmountpv.com and then attached the supporting rails via an L-bracket to the Quickmounts. Not a cheap solution but one in which I (and the roofer we consult with from time to time on installs) has high confidence. Scott. |
|
| Author: | sub3marathonman [ Tue Dec 09, 2008 9:42 am GMT EthGMT ] |
| Post subject: | Re: A question about roof mounting |
Wow, I hadn't know about those QuickMounts. I actually had a quote for them from Conergy where I purchased the mounting system, but all it said was "flashing" and it looked like incredibly expensive "flashing" so I passed. The "T-foot" is just an "L-foot" with an extra portion for another bolt into the rafter. It was my understanding that the "T-foot" is stronger than the "L-foot" so I went with the "T-foot." Also, there is apparently no QuickMount for a "T-foot." I was wondering if a person could make their own mount by drilling a square of aluminum for the lag bolt and putting that over the flashing. It appears that is what the QuickMount is, with the square apparently spot welded to the flashing. What I liked about the QuickMount is that it raised the panels another 1.5" above the roof so it should help keep the panels cooler. |
|
| Author: | WizBandit [ Mon Dec 15, 2008 10:04 pm GMT EthGMT ] |
| Post subject: | Re: A question about roof mounting |
We actually used OATEY solar flashings on ProSolar "legs". The legs are threaded and the base for them has one SS lag bolt that goes into the rafter under the leg. Take a look here: http://blog.robpatton.com/?cat=4 I sell them and have some in stock now. Officially they are called "FastJacks". http://www.prosolar.com/PDFS/BROCHURESp ... ochure.pdf |
|
| Author: | rayhat [ Wed Dec 17, 2008 1:49 pm GMT EthGMT ] |
| Post subject: | Re: A question about roof mounting |
I pilot drilled the rafters through the shingles, shot in some GEII Gutter silicone, siliconed the Stainless lag bolt, bottom of L foot, top of L foot, washer, and capped of lag bolt after tightening. This is how the installers by me do it. GOSOLAR.com based in NY. |
|
| Author: | solartek [ Wed Dec 17, 2008 2:22 pm GMT EthGMT ] |
| Post subject: | Re: A question about roof mounting |
rayhat wrote: I pilot drilled the rafters through the shingles, shot in some GEII Gutter silicone, siliconed the Stainless lag bolt, bottom of L foot, top of L foot, washer, and capped of lag bolt after tightening. This is how the installers by me do it. GOSOLAR.com based in NY. Really? No flashing at all? |
|
| Author: | rayhat [ Thu Dec 18, 2008 7:32 pm GMT EthGMT ] |
| Post subject: | Re: A question about roof mounting |
No flashing. Liberal amount of silicone, not a big mess. This is my first and only install, but I was in touch with the installers who do this week in and week out asking any simple question I had. The company has been doing this since 1979 so I feel confident about the install. Only time will tell. I also re-shingled over my original roof, so there are two layers of shingles on my roof. Since my last post, I saw some of the flashing mounts though and they look really nice. |
|
| Author: | sub3marathonman [ Fri Dec 19, 2008 12:45 am GMT EthGMT ] |
| Post subject: | Re: A question about roof mounting |
The current plan is to cut the shingle so the t-foot can stick up through it, with flashing underneath where the t-foot attaches. The roofer said that the shingle will somewhat conform to the foot during the hot summer. On some others I have seen the shingle cut out for the t-foot, with flashing underneath. It just seems keeping the shingle partially over the foot would help to protect things. I have also seen just slapping the t-foot on top of the shingles, and I guess that might be OK but you'll have to be much more vigilant about looking for deterioration and water leaks. I checked out the quickmounts, and they would be great except for the price. At $20/foot it gets expensive quickly. But they would have added a bit of height, and that would have helped to keep the panels cooler. Also, I then would have probably switched to the l-foot instead of the t-foot, which would have cut the number of mounting holes in half. I still wonder if that wouldn't have been the better way to do it, but I was told the t-foot was stronger so that's what I got. I also debated about getting 316 stainless lag bolts, which are supposed to be much stronger I guess, instead of 18-8 stainless lag bolts, even thinking of having one each for the t-foot, or else every other t-foot with 2 of the 316 bolts. But in the end I guessed that the 18-8 bolts would pull out of the rafter long before they would break. |
|
| Author: | jamesw [ Tue Jul 12, 2011 4:03 am GMT EthGMT ] |
| Post subject: | Re: A question about roof mounting |
Hi, I have been reading about quickmounts and it lead me to this thread. I have very limited idea over this so please spare me, do you need any support bracket so that you could get a steadier mount for the roof? I actually have no problem which how much it would cost just for the sake of getting a superior quality for a roof mount, which I am looking to last for quite a number of years. |
|
| Page 1 of 1 | All times are UTC - 5 hours [ DST ] |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|