Re: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?)
Glenn, I understand where you are coming from, However My concern is that flashings could be worse. Unless the flashing design supports sealant + flashing, it will most likely be worse. I've never seen a L-foot leak, but I've seem many flashings that rely on gravity leak. An L-foot sealed with silicone, holds that sealant in compression. It is a pretty ideal gasket. A flashing relies on gravity, but that only works until ice dams up. It also means you are modifying the roof to get the flashings under the shingles, which adds its own risk. After all, when roofs get low pitched enough, nobody uses gravity as a means of shedding water, they all use sealants or welded membranes. Nobody so far has commented on the code defensibility of sealant systems... it there anything in the code specific that is addressing this in the IRC/IBC? Or is it just a ICC rating issue that address assemblies? Yes it is more expensive – but it is like insurance, you don’t need it until you need it, but then there is no substitute for it. Of course if you are big enough with deep enough pockets you can take more chances with roof penetrations, and maybe you will not run into a call-back for a leaking roof. But if you do, wouldn’t you have a stronger position with the customer by saying all penetrations were flashed in accordance with standard roofing contractors and manufacturer’s specifications instead of ‘well I shot everything full of sealant and it is what I have been doing for years/hundreds of holes in roofs’… ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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
Re: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?)
Hi Glenn; How do you and the roofers deal with Propanel steel roofs? That's hundreds of penetrations for the screws, with no flashings, and they depend on just a little rubber gasket. Or how about the lead head nails on a corrugated metal roof? Roofers themselves make plenty of unflashed penetrations by your definition. Instead, I would call those roofing attachments, not penetrations. If I'm putting a 2 inch hole through a roof, then that constitutes a penetration, and using a flashing is usually a good idea. But when I'm filling a 1/4" hole with a 5/16" lag, its really much closer to being a roofing attachment than a penetration. BTW, we're not just depending on some adhesive to stop the moisture. An L foot is really a 1/4" thick aluminum flashing. It has at least 4 sq in. of surface area held permanently in place by a mechanical fastener that is applying a significant amount of downward pressure. Bulkheads on water tanks and boats use the same method, and hold not just against moisture intrusion, but moisture under pressure. How many PSI can a flashing take? With L feet, we're doing less damage to the roof underneath: one .05 sq in. hole through the roof, then covered by 80 times its surface area with 1/4" aluminum over a roofing approved sealant held mechanically under pressure. With flashings, you are tearing up the original roof, separating shingles from each other, ripping out mounting nails, tearing the undersides of the shingles, and removing many square inches of shingle off the roof, all to install a 200 sq in flashing to cover a 0.05 sq in hole. I've done it both ways, and I think you've got more of a chance of causing a leak installing flashings, especially on an older roof. Flashings make more sense on new construction, when the roofer can install the roof over the flashings after. The L foot mounting method was developed in the hot water days, and predates PV by over a decade. We've got more proven long term success with this mounting method than most module companies today can claim for their products (or makers of the latest flashings for that matter). Instead of all this knee jerk: flashing = good, L feet = bad, how about the roofing and solar industries coming up with actual testing to determine what mounting methods actually leak, and which ones don't? Meanwhile, many on the list have already pointed out: L feet installed with the correct sealant have lasted as long as the comp roofs they're on, 30 + years. Don't get me wrong, I use conventional flashings in many situations, especially on flat roofs. The Chemlink flashing is a favorite, but yes, it depends on chemicals to provide the moisture barrier, as do most roofing materials ( including comp roofs and most commercial flat roofs). Chemlink Flashing utilizes a 2 part adhesive process. R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760 On 4/13/2014 7:22 PM, Glenn Burt wrote: In New York solar installations are required to have all penetrations flashed chemical sealant is not flashing. Ask any roofer what he thinks about drilling through the roof and relying on purely a chemical adhesive/sealant for the prevention of water intrusion, and he will laugh at you. Glenn Burt One of many inspectors for the NYSERDA PV and Thermal incentive programs ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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
Re: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?)
In New York solar installations are required to have all penetrations flashed - chemical sealant is not flashing. An asphalt rooftop that sees temperature swings from -20 to 130F are a concern for simple thermal movement and I lost count of how many L feet I have seen with half a tube of silicone or worse yet Sikaflex goobered all around them. Ask any roofer what he thinks about drilling through the roof and relying on purely a chemical adhesive/sealant for the prevention of water intrusion, and he will laugh at you. NYS Building code 1503.2 is the primary reference for requiring flashing for all roof penetrations. The NYS 2010 residential code M2301.2.7, R903.2 all refer to 'flashing' and sealing. The National Roofing Contractors Association provides guidance for asphalt shingles and penetrations. Checking with many roofing manufacturers also has shown that they require flashing penetrations to maintain their warranties - not using flashing is a violation of the roofing installation instructions. Yes it is more expensive - but it is like insurance, you don't need it until you need it, but then there is no substitute for it. Of course if you are big enough with deep enough pockets you can take more chances with roof penetrations, and maybe you will not run into a call-back for a leaking roof. But if you do, wouldn't you have a stronger position with the customer by saying all penetrations were flashed in accordance with standard roofing contractors and manufacturer's specifications instead of 'well I shot everything full of sealant and it is what I have been doing for years/hundreds of holes in roofs'. I can't see in this day and age any reason not to use one of the many commercially available flashing solutions. Now 5 years ago, was a different time, and we formed our own flashing out of Al coil stock because there was no good solution available at that time. Hope this helps in your decisions. Glenn Burt One of many inspectors for the NYSERDA PV and Thermal incentive programs. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Troy Harvey Sent: Friday, April 11, 2014 3:20 PM To: RE-wrenches Subject: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?) 1. I'm interest in a poll of installers who are using flashings vs sealant. Now that the flashing market has evolved, what are you using today? When did you switch to flashings (if you did). And why not, if you still prefer sealant. 2. Is there a any code defense for sealant systems ? (L-foot sealed down to shingles). Does anyone know of a scientific shootout between sealants and flashings? Here is my view: The construction industry is slow to evolve. Sealants, clauks adhesives are not trusted in general, due to the legacy of code, and we have a mechanical vs. chemical industry bias. There is something about seeing a flashing that says, that is a professional job, it must comply with code. And yet, my experience says I'd trust a 50-year silicone over a flashing that depends on gravity. Gravity should be dependable right? But anyone in snow country can tell you in spring, water can go uphill after ice dams form. There are high-rise buildings that use structural glazing which is just glass and silicone. These systems are now getting to be 50 years old without issue. The cost of flashings have come down in the last few years, but so has the cost per watt of installs. With 50 feet in a typical install around here that is $150 in feet, lags silicone. Or $1500 in flashings, and extra labor. That can be a large part of a bid, and make you more expensive in a competitive landscape. That is fine, if it adds value... but I personally don't see the proven value, other than the appearance of code defensibility. Anybody have proof? thanks, Troy Harvey - Principal Engineer Heliocentric 801-453-9434 tahar...@heliocentric.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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
Re: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?)
Flashing only On Apr 11, 2014 9:20 AM, Troy Harvey tahar...@heliocentric.org wrote: 1. I'm interest in a poll of installers who are using flashings vs sealant. Now that the flashing market has evolved, what are you using today? When did you switch to flashings (if you did). And why not, if you still prefer sealant. 2. Is there a any code defense for sealant systems ? (L-foot sealed down to shingles). Does anyone know of a scientific shootout between sealants and flashings? Here is my view: The construction industry is slow to evolve. Sealants, clauks adhesives are not trusted in general, due to the legacy of code, and we have a mechanical vs. chemical industry bias. There is something about seeing a flashing that says, that is a professional job, it must comply with code. And yet, my experience says I'd trust a 50-year silicone over a flashing that depends on gravity. Gravity should be dependable right? But anyone in snow country can tell you in spring, water can go uphill after ice dams form. There are high-rise buildings that use structural glazing which is just glass and silicone. These systems are now getting to be 50 years old without issue. The cost of flashings have come down in the last few years, but so has the cost per watt of installs. With 50 feet in a typical install around here that is $150 in feet, lags silicone. Or $1500 in flashings, and extra labor. That can be a large part of a bid, and make you more expensive in a competitive landscape. That is fine, if it adds value... but I personally don't see the *proven* value, other than the appearance of code defensibility. Anybody have proof? thanks, Troy Harvey - Principal Engineer Heliocentric 801-453-9434 tahar...@heliocentric.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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: RE-wrenches@lists.re-wrenches.org Change email address 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
Re: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?)
We are the McDonalds of roof penetrations. During the last 30 years we have literally made pincushions of the roof we have worked on. After millions of unflashed penetrations we have only had one leak. Observing hundreds of Carter era systems we have never seen a mounting foot leak. Like Sasquatch sighting we have heard the stories. But from where we stand, we have seen exactly the same amount of both. Geography may be a key factor. We have used Vulcum and Dimonic we equal success. We are now forced to use flashing. Oregon specialty code forces every 24 when within 3' of a peak or edge. Where rafters are 16oc we are forced to install every 16. Outside of 3' every 48. The solar industry sleeps. On Apr 12, 2014, at 11:03 AM, Jerry Shafer jerrysgarag...@gmail.com wrote: Flashing only On Apr 11, 2014 9:20 AM, Troy Harvey tahar...@heliocentric.org wrote: 1. I'm interest in a poll of installers who are using flashings vs sealant. Now that the flashing market has evolved, what are you using today? When did you switch to flashings (if you did). And why not, if you still prefer sealant. 2. Is there a any code defense for sealant systems ? (L-foot sealed down to shingles). Does anyone know of a scientific shootout between sealants and flashings? Here is my view: The construction industry is slow to evolve. Sealants, clauks adhesives are not trusted in general, due to the legacy of code, and we have a mechanical vs. chemical industry bias. There is something about seeing a flashing that says, that is a professional job, it must comply with code. And yet, my experience says I'd trust a 50-year silicone over a flashing that depends on gravity. Gravity should be dependable right? But anyone in snow country can tell you in spring, water can go uphill after ice dams form. There are high-rise buildings that use structural glazing which is just glass and silicone. These systems are now getting to be 50 years old without issue. The cost of flashings have come down in the last few years, but so has the cost per watt of installs. With 50 feet in a typical install around here that is $150 in feet, lags silicone. Or $1500 in flashings, and extra labor. That can be a large part of a bid, and make you more expensive in a competitive landscape. That is fine, if it adds value... but I personally don't see the proven value, other than the appearance of code defensibility. Anybody have proof? thanks, Troy Harvey - Principal Engineer Heliocentric 801-453-9434 tahar...@heliocentric.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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: RE-wrenches@lists.re-wrenches.org Change email address 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: RE-wrenches@lists.re-wrenches.org Change email address 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
[RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?)
1. I'm interest in a poll of installers who are using flashings vs sealant. Now that the flashing market has evolved, what are you using today? When did you switch to flashings (if you did). And why not, if you still prefer sealant. 2. Is there a any code defense for sealant systems ? (L-foot sealed down to shingles). Does anyone know of a scientific shootout between sealants and flashings? Here is my view: The construction industry is slow to evolve. Sealants, clauks adhesives are not trusted in general, due to the legacy of code, and we have a mechanical vs. chemical industry bias. There is something about seeing a flashing that says, that is a professional job, it must comply with code. And yet, my experience says I'd trust a 50-year silicone over a flashing that depends on gravity. Gravity should be dependable right? But anyone in snow country can tell you in spring, water can go uphill after ice dams form. There are high-rise buildings that use structural glazing which is just glass and silicone. These systems are now getting to be 50 years old without issue. The cost of flashings have come down in the last few years, but so has the cost per watt of installs. With 50 feet in a typical install around here that is $150 in feet, lags silicone. Or $1500 in flashings, and extra labor. That can be a large part of a bid, and make you more expensive in a competitive landscape. That is fine, if it adds value... but I personally don't see the proven value, other than the appearance of code defensibility. Anybody have proof? thanks, Troy Harvey - Principal Engineer Heliocentric 801-453-9434 tahar...@heliocentric.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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
Re: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?)
Hi Troy, There has been an ongoing debate on the RE-Wrenches list on this issue for years now. I've personally serviced many old L-feet systems that are fine and some that are leaking. The leaks normally occur in the missed holes adjacent to the L-foot. Also, many installers were using Sikaflex which over time loses its adhesion to comp shingles. Sloppy work is the worst culprit. We've used all sorts of flashings over the years and primarily stick with Quickmount E-series these days. All holes, both hits and misses, are squirted with M-1 sealant (from Chemlink) and we slide aluminum flashing (standard rolls of aluminum cut to size in the field) under the shingles for the missed holes. We've never had a leak with a properly flashed system and I am a strong proponent for using flashing products for all mounting points. Best, August Luminalt *From:* re-wrenches-boun...@lists.re-wrenches.org [mailto: re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of *Troy Harvey *Sent:* Friday, April 11, 2014 12:20 PM *To:* RE-wrenches *Subject:* [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?) 1. I'm interest in a poll of installers who are using flashings vs sealant. Now that the flashing market has evolved, what are you using today? When did you switch to flashings (if you did). And why not, if you still prefer sealant. 2. Is there a any code defense for sealant systems ? (L-foot sealed down to shingles). Does anyone know of a scientific shootout between sealants and flashings? Here is my view: The construction industry is slow to evolve. Sealants, clauks adhesives are not trusted in general, due to the legacy of code, and we have a mechanical vs. chemical industry bias. There is something about seeing a flashing that says, that is a professional job, it must comply with code. And yet, my experience says I'd trust a 50-year silicone over a flashing that depends on gravity. Gravity should be dependable right? But anyone in snow country can tell you in spring, water can go uphill after ice dams form. There are high-rise buildings that use structural glazing which is just glass and silicone. These systems are now getting to be 50 years old without issue. The cost of flashings have come down in the last few years, but so has the cost per watt of installs. With 50 feet in a typical install around here that is $150 in feet, lags silicone. Or $1500 in flashings, and extra labor. That can be a large part of a bid, and make you more expensive in a competitive landscape. That is fine, if it adds value... but I personally don't see the *proven* value, other than the appearance of code defensibility. Anybody have proof? thanks, Troy Harvey - Principal Engineer Heliocentric 801-453-9434 tahar...@heliocentric.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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
Re: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?)
I've had a similar experience as August. We're using Ecofasten Green Flashing plus all holes get a dab of Geocel Proflex. We've also never had a problem with a properly flashed penetration. Thanks, Will From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of August Goers Sent: Friday, April 11, 2014 3:44 PM To: RE-wrenches Subject: Re: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?) Hi Troy, There has been an ongoing debate on the RE-Wrenches list on this issue for years now. I've personally serviced many old L-feet systems that are fine and some that are leaking. The leaks normally occur in the missed holes adjacent to the L-foot. Also, many installers were using Sikaflex which over time loses its adhesion to comp shingles. Sloppy work is the worst culprit. We've used all sorts of flashings over the years and primarily stick with Quickmount E-series these days. All holes, both hits and misses, are squirted with M-1 sealant (from Chemlink) and we slide aluminum flashing (standard rolls of aluminum cut to size in the field) under the shingles for the missed holes. We've never had a leak with a properly flashed system and I am a strong proponent for using flashing products for all mounting points. Best, August Luminalt From: re-wrenches-boun...@lists.re-wrenches.orgmailto:re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.orgmailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Troy Harvey Sent: Friday, April 11, 2014 12:20 PM To: RE-wrenches Subject: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?) 1. I'm interest in a poll of installers who are using flashings vs sealant. Now that the flashing market has evolved, what are you using today? When did you switch to flashings (if you did). And why not, if you still prefer sealant. 2. Is there a any code defense for sealant systems ? (L-foot sealed down to shingles). Does anyone know of a scientific shootout between sealants and flashings? Here is my view: The construction industry is slow to evolve. Sealants, clauks adhesives are not trusted in general, due to the legacy of code, and we have a mechanical vs. chemical industry bias. There is something about seeing a flashing that says, that is a professional job, it must comply with code. And yet, my experience says I'd trust a 50-year silicone over a flashing that depends on gravity. Gravity should be dependable right? But anyone in snow country can tell you in spring, water can go uphill after ice dams form. There are high-rise buildings that use structural glazing which is just glass and silicone. These systems are now getting to be 50 years old without issue. The cost of flashings have come down in the last few years, but so has the cost per watt of installs. With 50 feet in a typical install around here that is $150 in feet, lags silicone. Or $1500 in flashings, and extra labor. That can be a large part of a bid, and make you more expensive in a competitive landscape. That is fine, if it adds value... but I personally don't see the proven value, other than the appearance of code defensibility. Anybody have proof? thanks, Troy Harvey - Principal Engineer Heliocentric 801-453-9434 tahar...@heliocentric.orgmailto:tahar...@heliocentric.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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
Re: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?)
It definitely depends on the flashing. The Oatey type with the rubber gasket die after several years, and leak. For our installations, it really depends on the roof. In some cases with metal roofs, a flashing can't really have the overlap needed, and so it just becomes a big gooed on L foot really. Also, I look at L feet as a small 2 x 2 flashing. Relative to the hole size this is often a reasonable amount of sealing surface. Compare this to your average 4 plumbing penetration vs the size of the flashing. Look at how bulk head fittings on water tanks work. They're under several feet of water, and depend on a rubber gasket, not a flashing. I also consider what's under the roof too. A leak on an open carport is not as much liability as a leak over the vintage Steinway grand piano. Finally, if the roof is already having problems, (I love when they say: it only leaks when it rains..) you need to look at re roofing, and have the roofer seal around your mounts. R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760 On 4/11/2014 1:52 PM, Will White wrote: I've had a similar experience as August. We're using Ecofasten Green Flashing plus all holes get a dab of Geocel Proflex. We've also never had a problem with a properly flashed penetration. Thanks, Will *From:*re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of *August Goers *Sent:* Friday, April 11, 2014 3:44 PM *To:* RE-wrenches *Subject:* Re: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?) Hi Troy, There has been an ongoing debate on the RE-Wrenches list on this issue for years now. I've personally serviced many old L-feet systems that are fine and some that are leaking. The leaks normally occur in the missed holes adjacent to the L-foot. Also, many installers were using Sikaflex which over time loses its adhesion to comp shingles. Sloppy work is the worst culprit. We've used all sorts of flashings over the years and primarily stick with Quickmount E-series these days. All holes, both hits and misses, are squirted with M-1 sealant (from Chemlink) and we slide aluminum flashing (standard rolls of aluminum cut to size in the field) under the shingles for the missed holes. We've never had a leak with a properly flashed system and I am a strong proponent for using flashing products for all mounting points. Best, August Luminalt *From:*re-wrenches-boun...@lists.re-wrenches.org mailto:re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org mailto:re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of *Troy Harvey *Sent:* Friday, April 11, 2014 12:20 PM *To:* RE-wrenches *Subject:* [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?) 1. I'm interest in a poll of installers who are using flashings vs sealant. Now that the flashing market has evolved, what are you using today? When did you switch to flashings (if you did). And why not, if you still prefer sealant. 2. Is there a any code defense for sealant systems ? (L-foot sealed down to shingles). Does anyone know of a scientific shootout between sealants and flashings? Here is my view: The construction industry is slow to evolve. Sealants, clauks adhesives are not trusted in general, due to the legacy of code, and we have a mechanical vs. chemical industry bias. There is something about seeing a flashing that says, that is a professional job, it must comply with code. And yet, my experience says I'd trust a 50-year silicone over a flashing that depends on gravity. Gravity should be dependable right? But anyone in snow country can tell you in spring, water can go uphill after ice dams form. There are high-rise buildings that use structural glazing which is just glass and silicone. These systems are now getting to be 50 years old without issue. The cost of flashings have come down in the last few years, but so has the cost per watt of installs. With 50 feet in a typical install around here that is $150 in feet, lags silicone. Or $1500 in flashings, and extra labor. That can be a large part of a bid, and make you more expensive in a competitive landscape. That is fine, if it adds value... but I personally don't see the /proven/ value, other than the appearance of code defensibility. Anybody have proof? thanks, Troy Harvey - Principal Engineer Heliocentric 801-453-9434 tahar...@heliocentric.org mailto:tahar...@heliocentric.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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
Re: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?)
I would have to definitely lean towards using flashings as a default and have been doing so now for several years. Last project i wanted to use flashings on and couldn't was in 2010. I couldn't because it was a 10-13 deg slope with asphalt shingles that were really good quality and made for low slope and resistant to high wind, this meant that each course of shingle was very well adhered to the course below it, to the point that it was next to impossible to lift the shingles to insert a flashing. I tried everything short of using a heat gun or torch to warm them up first. I cannot quote anything, but i believe that there is an issue with voiding roof warranties if you do not flash a penetration. Always make sure that the sealant you choose is compatible with the roof and any other material it will contact. I believe there was an issue years ago where many installers were using a popular sealant that (if you read the small print) was not compatible with asphalt shingles. My sealant of choice these days is Henry 925. I would be very interested to see, if anyone would be willing to share (on or off-list), photos of any signs of leaking or leak damage caused by failed roof penetrations. Cheers, Benn On Fri, Apr 11, 2014 at 1:20 PM, Troy Harvey tahar...@heliocentric.orgwrote: 1. I'm interest in a poll of installers who are using flashings vs sealant. Now that the flashing market has evolved, what are you using today? When did you switch to flashings (if you did). And why not, if you still prefer sealant. 2. Is there a any code defense for sealant systems ? (L-foot sealed down to shingles). Does anyone know of a scientific shootout between sealants and flashings? Here is my view: The construction industry is slow to evolve. Sealants, clauks adhesives are not trusted in general, due to the legacy of code, and we have a mechanical vs. chemical industry bias. There is something about seeing a flashing that says, that is a professional job, it must comply with code. And yet, my experience says I'd trust a 50-year silicone over a flashing that depends on gravity. Gravity should be dependable right? But anyone in snow country can tell you in spring, water can go uphill after ice dams form. There are high-rise buildings that use structural glazing which is just glass and silicone. These systems are now getting to be 50 years old without issue. The cost of flashings have come down in the last few years, but so has the cost per watt of installs. With 50 feet in a typical install around here that is $150 in feet, lags silicone. Or $1500 in flashings, and extra labor. That can be a large part of a bid, and make you more expensive in a competitive landscape. That is fine, if it adds value... but I personally don't see the *proven* value, other than the appearance of code defensibility. Anybody have proof? thanks, Troy Harvey - Principal Engineer Heliocentric 801-453-9434 tahar...@heliocentric.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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: RE-wrenches@lists.re-wrenches.org Change email address 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
Re: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?)
Hi Ray, Ten plus years ago, I observed this one thermal installation which also used the Oatey flexible gasket. Most all the 80's era installs had seriously deteriorated gaskets _except_ this one where the homeowner had painted everything with latex paint. That gasket was not deteriorated and was still flexible. That small UV film barrier was really beneficial. Automotive CV boots are available with a split for replacement use. I'm told that if you allow the glue to dry properly (without moving the steering wheel) it works as good as the non split model. I would not be surprised if a similar product exists for plumbing/electrical penetrations. With paint, that should be the last gasket replacement. Good luck all, Bill Loesch Solar 1 - Saint Louis Solar 314 631 1094 On 11-Apr-14 3:15 PM, Ray Walters wrote: It definitely depends on the flashing. The Oatey type with the rubber gasket die after several years, and leak. For our installations, it really depends on the roof. In some cases with metal roofs, a flashing can't really have the overlap needed, and so it just becomes a big gooed on L foot really. Also, I look at L feet as a small 2 x 2 flashing. Relative to the hole size this is often a reasonable amount of sealing surface. Compare this to your average 4 plumbing penetration vs the size of the flashing. Look at how bulk head fittings on water tanks work. They're under several feet of water, and depend on a rubber gasket, not a flashing. I also consider what's under the roof too. A leak on an open carport is not as much liability as a leak over the vintage Steinway grand piano. Finally, if the roof is already having problems, (I love when they say: it only leaks when it rains..) you need to look at re roofing, and have the roofer seal around your mounts. R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760 On 4/11/2014 1:52 PM, Will White wrote: I've had a similar experience as August. We're using Ecofasten Green Flashing plus all holes get a dab of Geocel Proflex. We've also never had a problem with a properly flashed penetration. Thanks, Will *From:*re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of *August Goers *Sent:* Friday, April 11, 2014 3:44 PM *To:* RE-wrenches *Subject:* Re: [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?) Hi Troy, There has been an ongoing debate on the RE-Wrenches list on this issue for years now. I've personally serviced many old L-feet systems that are fine and some that are leaking. The leaks normally occur in the missed holes adjacent to the L-foot. Also, many installers were using Sikaflex which over time loses its adhesion to comp shingles. Sloppy work is the worst culprit. We've used all sorts of flashings over the years and primarily stick with Quickmount E-series these days. All holes, both hits and misses, are squirted with M-1 sealant (from Chemlink) and we slide aluminum flashing (standard rolls of aluminum cut to size in the field) under the shingles for the missed holes. We've never had a leak with a properly flashed system and I am a strong proponent for using flashing products for all mounting points. Best, August Luminalt *From:*re-wrenches-boun...@lists.re-wrenches.org mailto:re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org mailto:re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of *Troy Harvey *Sent:* Friday, April 11, 2014 12:20 PM *To:* RE-wrenches *Subject:* [RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?) 1. I'm interest in a poll of installers who are using flashings vs sealant. Now that the flashing market has evolved, what are you using today? When did you switch to flashings (if you did). And why not, if you still prefer sealant. 2. Is there a any code defense for sealant systems ? (L-foot sealed down to shingles). Does anyone know of a scientific shootout between sealants and flashings? Here is my view: The construction industry is slow to evolve. Sealants, clauks adhesives are not trusted in general, due to the legacy of code, and we have a mechanical vs. chemical industry bias. There is something about seeing a flashing that says, that is a professional job, it must comply with code. And yet, my experience says I'd trust a 50-year silicone over a flashing that depends on gravity. Gravity should be dependable right? But anyone in snow country can tell you in spring, water can go uphill after ice dams form. There are high-rise buildings that use structural glazing which is just glass and silicone. These systems are now getting to be 50 years old without issue. The cost of flashings have come down in the last few years, but so has the cost per watt of installs. With 50 feet in a typical install around here
