This was brought up in a previous thread possibly years ago, but we can't use Geocel 4500 in at least one jurisdiction here because it lacks ASTM testing to some required standards that the AHJ is looking for. I can't remember if that was D4586 or C920. I confirmed with Geocel at the time that the lack of testing was accurate. That's too bad, because it does exceptionally well. Geocel 2300, 3300, and 4300 have the ASTM testing behind those products. We have moved on to Chemlink M-1 which I have been impressed with.
Of note is that IronRidge does not require (nor prohibit) the use of any sealants with FlashVue. I plan to use sealants with FlashVue due to the prevalence of wind driven rain around here. Jason On Wed, Apr 21, 2021, 12:23 PM frenergy <frene...@psln.com> wrote: > OK, I'll stick my neck out. We've done very few flashings on comp for the > last 18 years or so, using (first) the highest quality polyurethane caulk > we could find. However, for the last 10 years we've been using Geocell > 4500 which states on the tube that it is compatible with asphalt/comp > shingles. For a variety of reasons not related to leaks, we've had to pull > some of these L-feet to which we saw there was a bond/seal to the shingle > like it had been welded to it. The Geocell was still extremely flexible. > > Whenever (infrequently) there's a chance we look for stains on > roof decking and rafters if we're in the attic of an old install. Of > course there is the need to think about what you're doing when your > applying the bead with regard to location and quantity of caulking and be > conscious of torque applied to the lag bolt, being sure you get some > caulking squeezed out the side of the L-foot, covering the head of the lag > bolt with caulk also. Its a bit of an art we take seriously. So far as we > know, no leaks with thousands of L-feet. > > Oh, and flashings are good too, but are not perfect. > > Bill > > Feather River Solar Electric > Bill Battagin, Owner > 4291 Nelson St. > Taylorsville, CA 95983 > 530.284.7849 > CA Lic 874049www.frenergy.net > > On 4/21/2021 7:40 AM, Jeremy Coxon wrote: > > I’m interested in what the group has to say about the trend, by the > racking manufacturers, away from the use of flashings for asphalt/comp > roofs? We have long used SnapNRack flashings with much success. I > especially like the fact that the penetrations are fully flashed and do not > rely on sealant. I am NOT a fan of their new raised cone/epdm gasket > flashing. There are a number of these raised cone flashings in the > marketplace and it’s my experience that they don’t hold up to the test of > time and I wonder what the roofing manufacturers have to say about this. > > I see that Unirac, SnapNRack and others are now offering basically a > sealed L-Foot which is essentially where we were 15-16yrs ago and met with > a lot of opposition from the roofing industry. Just interested to hear > what you guys are using these days on asphalt shingle roofs for reliably > dry attachments? > > Best Regards, > Jeremy Coxon NABCEP # 091308-21 > MWBE Certified > > > > >
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