I've found that the Flashed L-Foot connection costs about $0.10/w on a typical residential system, and only adds about 1/4-1/2" to the height, which can be minimized using the slotted holes in a typical L-Foot. We need a lot of attachments for 172 mph design wind speeds around here. Flashings at $500 for a 5kW seems high, especially now as the percentage of the system price increases. That being said, I would install L-Foot flashings on my own roof - no exceptions.
On the other hand, I've seen sealed lag screw connections work with solar pool heating systems for decades without indication of problems. A variety of sealants were used in the "old days" but most recently Sikaflex 1A (which incidentally is not indicated for asphaltic roofs) and Geocell 2300 have worked great. My 10 cents, :) Jason Szumlanski Fafco Solar On Fri, Jun 29, 2012 at 10:49 AM, jay peltz <[email protected]> wrote: > I have had the opportunity in the past few years to learn a lot about > good roofing waterproofing practices according to the national roofers > association. > > They don't agree that caulk works as the primary means of sealant, which > is what you are doing with an L foot. > > And given that we have really good off the shelf approved flashed feet, > why would you use anything else? > > My 2 cents, > > Jay > > peltz power > > > On Jun 29, 2012, at 5:16 AM, Glenn Burt wrote: > > We have used a variety of sealants over the years, and determined simple > Henry roofing cement is the best product for use on comp roofing.**** > ** ** > We also used to bend our own L-foot flashing, which we cut from standard > Al coil stock (before all the manufactured options were available). This > might be a good option for you in this case.**** > ** ** > ** ** > ** ** > Glenn**** > ** ** > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Drake > *Sent:* Thursday, June 28, 2012 6:40 PM > *To:* RE-wrenches > *Subject:* [RE-wrenches] L feet no flashing in shingle roof**** > ** ** > I'm quoting a job that has an existing array with L feet bolted down to a > shingle roof with no flashings. I want to match the height of the existing > array. Also some modules are being worked in around skylights where it is > unlikely that room would be available for flashings to center over rafters. > > I've always used flashings. Would it be completely crazy to follow suit > of the existing array and bolt L feet straight to the shingle roof with > good roof sealant? If so, how would you seal it? > > Thanks, > > Drake > > **** > > Drake Chamberlin > ATHENS ELECTRIC LLC > OH License 44810 > CO license 3773 > NABCEP Certified PV**** > > > > _______________________________________________ > 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
