Issue: Corrosion of fasteners used to secure metal ridge vent system on shingle and tile roofs

Concerns raised by the attached letter:

- Severe corrosion was fairly consistent, specifically with the use of electro-galvanized fasteners.

- Similar corrosion problems in fasteners used to secure the new metal ridge backing accessories being utilized with concrete and terra cotta roof tile systems.

- Significantly more serious in coastal environment due to presence of chloride ions.

- Increase in manufacturing of these products outside the United State,

2010 Florida Building Code:

Non-HVHZ

1506.4 Product identification.

Roof-covering materials shall be delivered in packages bearing the manufacturer’s identifying marks and approved testing agency labels required in accordance with Section 1505. Bulk shipments of materials shall be accompanied with the same information issued in the form of a certificate or on a bill of lading by the manufacturer.

1506.5 Nails.

Nails shall be corrosion resistant nails conforming to ASTM F 1667. The corrosion resistance shall meet ASTM A 641, Class 1 or an equal corrosion resistance by coating, electro galvanization, mechanical galvanization, hot dipped galvanization, stainless steel, nonferrous metal and alloys or other suitable corrosion resistant material.

1506.6 Screws.

Wood screws conform to ANSI/ASME B 18.6.1. Screws shall be corrosion resistant by coating, galvanization, stainless steel, nonferrous metal or other suitable corrosion resistant material. The corrosion resistance shall be demonstrated through one of the following methods:

1. Corrosion resistance equivalent to ASTM A 641, Class 1;

2. Corrosion resistance in accordance with TAS114, Appendix E; or

3. Corrosion resistant coating exhibiting not more than 5 percent red rust after 1000 hours exposure in accordance with ASTM B 117.

1506.7 Clips.

Clips shall be corrosion resistant clips. The corrosion resistance shall meet 0.90 ounce per square foot (0.458 kg/m2) measured according to ASTM A 90/A 90M, TAS 114 Appendix E or an equal corrosion resistance coating, electro galvanization, mechanical galvanization, hot dipped galvanization, stainless steel, nonferrous metals and alloys or other suitable corrosion resistant material. Stainless steel clips shall conform to ASTM A167, Type 304.

HVHZ

1517.5 Fasteners.

1517.5.1

Nails shall be minimum 12 gage, annular ring shank nails having not less than 20 rings per inch, heads not less than 3/8 inch (9.5 mm) in diameter; and lengths sufficient to penetrate through the thickness of plywood panel or wood plank decking not less than 3/16 inch (4.8 mm), or to penetrate into a 1 inch (25 mm) or greater thickness of lumber not less than 1 inch. Nails or wood screws shall be hot dipped electro or mechanically galvanized to a thickness sufficient to resist corrosion in compliance with TAS 114, Appendix E, Section 2 (ASTM G 85). All nails shall be listed by a certification agency. All nail cartons or carton labels shall be labeled to note compliance with the corrosion resistance requirements. No roofing material shall be fully or partially adhered directly to a nailable deck, unless otherwise noted in the roof assembly Product Approval.

1517.5.2

Such fasteners shall be applied through “Tin caps” no less than 15/8 inches (41 mm) and not more than 2 inches (51 mm) in diameter and of not less than 32 gage (0.010 inch) sheet metal. “Cap nails” or prefabricated fasteners with integral heads complying with this section shall be an acceptable substitute. All “tin caps,” “cap nails” or prefabricated fasteners with integral heads shall be tested for corrosion resistance in compliance with TAS 114, Appendix E, Section 2 (ASTM G 85), and shall be product control listed. All of cartons or carton labels “tin caps,” “cap nails” or prefabricated fasteners with integral heads shall be labeled to note compliance with the corrosion resistance requirements.

ECTION 1523 HIGH-VELOCITY HURRICANE ZONES— TESTING

1523.6.5.2.10 Roofing nails and tin-caps.

All roofing nails and tin-caps shall be tested for corrosion resistance in compliance with TAS 114, Appendix E, Section 2 (ASTM G 85).

1523.6.5.2.11 Roof tile nails or fasteners.

All roof tile nails or fasteners, except those made of copper, monel, aluminum or stainless steel, shall be tested for corrosion in compliance with TAS 114, Appendix E, Section 2 (ASTM G 85), for salt spray for 1000 hr.

1523.6.5.2.11.1

Tile fasteners used in coastal building zones, as defined in Chapter 16 (High-Velocity Hurricane Zone), shall be copper, monel, aluminum or stainless steel.

TESTING APPLICATION STANDARD (TAS) No. 114-11 TEST PROCEDURES FOR ROOF SYSTEM ASSEMBLIES IN THE HIGH-VELOCITY HURRICANE ZONE JURISDICTION

8.4 Corrosion Resistance:

8.4.1 Nails and carbon steel fasteners:

8.4.1.1 All nails and carbon steel fasteners shall be tested for corrosion resistance in compliance with ASTM Standard Practice G 85 [(Modified Salt Spray (Fog) Testing)], Annex A5 (Dolute Electrolyte Cyclic Fog/Dry Testing) as modified for the highvelocity hurricane zone and noted in Section 2 of Appendix E, herein.

8.4.2 Batten bars, stress distribution plates and fasteners (other than nails):

8.4.2.1 All batten bars, stress distribution plates, and metal fasteners (other than nails) shall be tested for corrosion resistance in compliance with DIN 50018 as noted in Section 3 of Appendix E, herein.

8.4.2.2 Each specimen shall be exposed to air saturated with water vapor (104°F, 40°C) containing a mild concentration of sulfur dioxide for 8 hours, followed by a drying period of 16 hours at room temperature. After each drying cycle, the specimen shall be inspected and signs of corrosion or rust shall be recorded.

8.4.2.3 The 24-hour cycle shall be repeated 15 times and the corrosion percentage shall be recorded.

8.4.2.4 To evaluate the corrosion increase after Cycle 1 through Cycle 15, the specimen shall be mounted to blue painted sheet backdrop.

State Product Approval:

Currently, there are 17 ridge vents products approved under the State Product Approval Program.

Method of compliance – Certification

Attachment:

Ridge vent:

Product/Roofing nails; Dimensions/min. 12 ga; Test specification/TAS 114 Appendix E; Product description/Corrosion resistant annular ring shank nails; Manufacturer/generic.

Ridge shingle: Using nail lines provided on top of vent. Install the cap shingles directly to the vent in the normal manner, using roofing nails of sufficient length to penetrate the sheathing a minimum of 3/16” or at least 1” into wood plank decking thicker than 1”.

Align end of first section on the end marks and the bottom of the nailing flange on the chalk line (4" down on both sides of the ridge peak for VUR vent; 5¼" down on both sides of the ridge peak for LPR vent). Nail the VUR & LPR Ridgevent in place using 11 gauge 2" galvanized smooth shank roofing nails through the factory formed holes, with the first nail 1½" to 2" form the vent end. All nail heads and vent section joints shall be sealed with 100% silicone sealant

Install Hurricane straps over each end of ridge vent, all connections between sections and at 3 feet intervals over the reminder of the vent using four 1 ½ “ galvanized ring shank-roofing nails per strap.

Nail – Length = 2. 5”; Diameter = 0.125”; TAS 114 Appendix E; Corrosion resistance nail for use with vent.

Fasten the ridge shingles over the vent to the deck on the marked “shingle nail line” with (2) nails. Outside of the shingles are to be sealed with flashing cement.

Installation: vents should be evenly spaced on the rear slope of the roof.

Center vent in opening and set it in a 1/8” thick of asphalt roofing cement. Secure vent to the roof deck with 1-1/4” galvanized ring shank roofing nails spaced approx. 8” o.c. and 1” from the outside edge of the flange. Use a minimum of 18 nails per vent. Seal all nails and vent flange with an approved ASTM D 4586 roofing cement.

Evaluation report – From an engineer

Fastener:

Ridge vent to Deck – Type: annular ring shank roofing nails.

Size – 11 ga. x 1-1/4”.

Corrosion resistance- per FBC Section 1506.5.

Standard: Per ASTM F 1667.

Ridge vent: use nail at least 1 ¾” or larger. Nails must always penetrate through plywood decks at least ¾” into wood planks.

Shingles:

Fasten each piece with two corrosion resistant, minimum 0.118-inch shank-diameter, minimum 1¾-inch long, deformed shank nails with minimum 3/8-inch head diameter. Nail through the reinforced exposed plastic cross hatched nail zone at the rear of each piece. For increased wind resistance, add two nails, 1-inch further in from the first nail. For a total of four nails per piece. In addition to these nails, the leading edge of the first piece may be face nailed as well. Ensure nails penetrate through the plastic backer and into the deck below. Exposed nail heads must be properly sealed with roofing cement or silicone sealant. NOTE: The use of excess roofing cement can cause blistering of the asphalt shingle.

_____________________________________________________________________________________Notes from the May 31, 2013 Roofing TAC Meeting

- In high salt environments even connectors don’t last, if they’re hot dipped zinc-galvanized don’t last, but maybe five to six years in the high salt environments.

- it seems to me that this is a product control issue that Product Approval, the POC, should be looking at to make sure that the fasteners that are supplied with the products are in fact meet the standards that they tested to for their product approval.

- The test standards on the Miami-Dade product approval say it’s to meet TAS 114 and generic. So, I’m certain that this product is manufactured for…..and I would assume that maybe the fasteners that come in the package aren’t really the fasteners that are supposed to meet the standards for the state of Florida and the salt water testing and everything. But maybe that’s an issue that needs to be addressed through Product Approval, that if you’re distributing this product in our state you have to meet the fastener approval that’s there.

- With respect to galvanizing, TAS 114 gives a number of different allowances. Galvanizing is under Appendix D-E and that is the least restrictive of any of the galvanizing techniques and A-3, test would certainly be a better test.

- Do the nails always come in the package with the vent or are they supplied as a separate item by the installer?

- The Notice of Acceptance in question has limits of use in requiring that the nails used are compliant with the TAS 114 corrosion testing. For that we do have a separate listing of nails and different types of fasteners that are compliant with that standard so that could be selected off of that list. If the nails or fasteners are supplied with the louver or with the vents it would need to be indicative of being compliant with that standard or the roofer could use nails or fasteners off of any of the distributors that are listed on that separate listing.

- Regarding the corrosion issue, we here in Miami-Dade County have not experienced this type of problem with the corrosion because of these checks and balances that have been put in place. I don’t know all of the details, and I’ve tried to look at the minutes of what was uploaded on the website but it’s not clear to me as to how different nails or if even it was those nails that got down to those jobs there in the non-high velocity areas.

- In May 18, of 2011, Eric Smith, a local roofing contractor brought this issue to the Building Code Advisory Board and the issue that he brought up was, he had observed that on his jobs that nails were failing on these ridge vents after a few years of exposure to our environment. And he brought it as a, you know, kind of a, just an awareness thing. He had gone back on his own and replaced several that he himself had installed in an attempt to provide a quality product. I think in the end nobody thought that this product was at fault or the approval agency was at fault. The corrosion nails are, resistant nails, are supplied with the vent. What happens, it appears to be an inherent failure that comes up after the product has been used for a while and time reveals possibly a design flaw that would not have been seen upfront. And that would be where the nails are installed and they’re installed properly, but the corrosion resistant coating, the galvanization gets scraped going through during the installation process. This happens anytime you use a nail like that, but normally it’s imbedded and is not going to be exposed to the environment. With the ridge vents, the way these are installed, there’s portions of a nail that are exposed to the environment and then once that galvanized coating gets scratched it opens the nail up to getting corroded. So I think that was the point being brought up was this is happening; how do we move forward with correcting that, not pointing blame backwards, but how do we go forward to make sure this is a quality product.

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- One of the other problems that I observed when we were talking about the coastal environment, Wellington is way west of the coastal environment and we were seeing a lot of problems out there, not only with the ridge vents, but there were several roofs, shingle roofs, that had nail heads that were completely rusted away on a roof that was probably about 7 or 8 years old and the roof pitch was 4 ½ /12 and I believe the other one was around a 5/12.

- I wanted to try to give you some background on our process here and what may be going forward. First, I would agree with Mr. Byrne that we also have seen lots of issues with corrosion of fasteners, not only in coastal areas of Florida but also inland areas, far inland, some of which are only four years old where the nails have corroded off. So, it’s not totally the nails that are used with the ridge vents although, I do agree with the gentlemen that spoke previously to Mr. Byrne that there is potential for the electro-galvanic plating to come off or be scraped off as the nails are being driven through the ridge vents and those nails are much more exposed than the nails in shingles. There is a wide-spread problem with the corrosion of fasteners. So that’s kind of a historical note. As far as the fasteners that we ship with our products our standard practice is to not ship the ridge vent products with the nails into the Florida market. But on occasion that does happen. If somebody orders a half truck of one product and a half truck of another product, and a lot of times that product – the ridge roll vent that we are discussing here – is shipped into Florida with nails. That’s not our intent but it does happen. That being said, I’ve looked into the supplier of the nails and the standards, codes and standards criteria of the nails. Those nails are listed and labeled that they do meet the criteria of ASTM A-641. So if I’m reading TAS 114 correctly, that is an alternate path of compliance for your resistance of nails and they are labeled as such in the original box. When we ship them with our roll vents they are not packaged in a box. They are in a collated coil and put into the center of the roll. But I have been assured by the manufacturer of the nails that they are tested to that standard.

I checked into our claims that have been filed for this issue and we don’t have any claims on record in our warranty data base that indicates that anyone has come back to us and said ‘hey, we are having issues with the fasteners that are being shipped with your product can you have somebody come down and look at this.’ So, without the benefit of actually having seen any of these jobs, it would be very difficult for me to say, or for anyone to say really, what the core cause of the corrosion is, whether it’s faulty cleaning or whether it’s faulty installation.

- The reason I participated in the call is we, as a corporation, are very interested in what happens in Florida in regards to fasteners that are exposed. The bulk of our fastener business in Florida is with roofers and we see a wide range of products being used in environments, not necessarily coastal, but inland and coastal. It’s important to note that there is a huge difference with ferrous metal fasteners when we’re just talking about plating versus coating. By its nature, ferrous metal fasteners, sacrificial to whatever it’s penetrating, whether that’s galv-alum or galvanized steel or aluminum which is not good, but what we typically do with our fasteners, our threaded fasteners, is a try-seal coating which meets a 1000 hour salt spray test. What we have found in terms of price and performance, which is important to all these guys, it seems to be the best marriage, if you will.

- I’ve been listening to a lot of the conversation. I’ve actually been in the fastener industry for over 30 years, everywhere from the manufacturing arm to the distribution arm. And I’ve realized that there are some issues with product control. I think a lot of it has to do with – an issue has to do with the manufacturing of the product through the distribution arm. Of course, the manufacturer is responsible to provide, consistently provide the product that the distribution arms are purchasing. But at the same time, the distribution arm should be responsible to have a consistent quality control when these products come from the manufacturer to their distribution facilities. A lot of it, I believe is, there is not a clear understanding of different types of coatings that are being put, especially on these roofing nails that are out in the market. Many electro-galvanized type nails have to have a minimum coating, I believe in microns, of between 8 and 12 microns, consistently on these roofing nails to consistently meet the TAS 114, Appendix E, G85 test. My curiosity is, with that test, how many years does this test represent? That’s question #1.

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- And #2, I truly don’t believe that are being placed in these boxes, are truly what they should be. And I think that enforcement of the Code needs to be strict, more strict, on the random control testing. And I believe that it has to be educated better on exactly how these coatings or these sacrificial coatings are being used. What are they and how do they react?

- First of all, G85 does not give you a period of time. It is an agreement between a manufacturer and the guys running the G85 test. However, TAS 114.11 is, taking your choice on nails, is 80 cycles, two hours each, so you talking about 90 hours of actual in the box exposure or 3.75 days. Where the … cabinet test is about 1000 hours. A hell of a lot of difference between a 90 hour test and that’s why in my opinion, Appendix E is not sufficient. When you talk about stainless, I have yet to see a 316 stainless corrode like that. I have seen 400 series corrode and I’ve seen a lot of mix up between 300 and 400 series.

- How long are those fasteners to be exposed to elements and we have no idea what other elements were around those specific sites that may have caused those fasteners to corrode, but if we’re having exposed fasteners in a product, then what is that time-frame that meets a product approval.

- As part of the requirement for nails, it would be the Code required or prescribed hours of exposure. And currently, for this type of an application it requires 280 hours under that TAS 114, Appendix E test. Correlation or what that would equate to life of the product is very dependent on location of where it is installed.

- So, with that given fact, and the statements that were made today of the time frame that this has happened, may I ask what the objective is? I mean, if an exposed fastener lasted 5 to 7 years, and it was electro-galvanized and not knowing the elements, obviously it is the assumption that it met product approval and was installed properly, so what is our objective of what was brought before the Committee today, with the fact that everything was met from a Code standard?

- Unfortunately, we’re listening, although truthful, we’re listening to anecdotal issues and I’m not so sure this TAC can really change the Code based on just some anecdotal issues and we need to probably gather a little more information in order to suggest a change in the Code.

- Not being a big shingle guy, and just sitting back listening to the conversation, I’m wondering if we’re in a situation where, with this particular ridge vent with these particular fasteners, if we have fasteners that are exposed to the elements versus concealed fasteners, i.e. 280 cycle or 280 hour tested fasteners that are typically concealed, versus a fastener where it’s being utilized with this particular product where it is being exposed to the elements? At which point I would make the analogy over to a roof tile fastener in a high velocity hurricane zone that then has to meet the 1000 hour salt spray. I wonder if Miami-Dade knew if this fastener was going to be exposed to the elements versus being concealed, as is with the other mechanical fasteners. I’m just wondering if this fastener should be 1000 hour salt spray versus a 280 cycle.

- What would be the next higher quality fastener that could be used? I’m assuming that it would be stainless steel and if a stainless steel nail was used, would that limit the corrosion failure?

- Yes, ah, looking at the, ah, NOA and the installation instructions, I really don’t see where these types of fasteners are exposed. They should be covered by shingles. And, ah, are we, I want to make sure that we’re going by the installation instructions and they’re being installed correctly, first, because I think your problem will arise if you have those fasteners exposed.

- I can address that. They would be exposed through the cross section of the vent. The vent is porous in the horizontal direction, and so the shank of that nail would be exposed by virtue of the porous nature of that vent.

- The product approval that we’re looking at on page 3 of 4, if you read through the installation guidelines, the only use for the nails that are associated with this product approval are the fasteners that you use to set the ridge vents in place. And that’s it. It just holds it in place until you start putting the ridge cap pieces, the asphalt shingle ridge cap pieces on, and it just says, it tells you to use roofing nails that are going to penetrate through the wood deck at least a half inch. So it’s not a product approval issue. The fasteners that they’re talking about are fasteners that are outside the scope of this particular product approval. I mean if the manufacturers of the ridge vent give you the fasteners for that product, for that product and the installation of those shingles, and how are they going to know what depth that’s going to be, depending on the deck size and all that. So, I don’t know that there’s too many that have that. They may have it and I don’t know. But that would be a, in this particular case, that’s really not an issue.