| Author |
Message |
Robin E. Snyder
Senior Member
Username: robin
Post Number: 411
Registered: 08-2004
| | Posted on Tuesday, June 19, 2012 - 11:34 am: |    |
I’m looking for some input regarding a horrible metal siding installation on a small condo property in Colorado. I own a unit there and am trying to assist the HOA in convincing the contractor the installation is unacceptable without resorting to litigation. The metal siding is on a mansard roof, exposed fastener system. The fasteners were placed through the high point of the ribs and overdriven, resulting in substantial denting of the panels. The contractor has offered to loosen the fasteners which, supposedly, makes the metal “undimple”. I am asserting that it is unacceptable to fasten through the ribs – has anyone seen when this is acceptable? (Contractor says it is typical in areas where there are huge temperature swings such as the Rockies, but I assert the opposite – that the fasteners are more prone to movement and breakage if they are spanning the distance from the high rib to the sheathing). I also believe that the pull-strength of the fastener is reduced when overdriven and will be reduced further by loosening the fastener. And, of course, metal doesn’t just “pop back” into flat. Is anyone familiar with any industry standards (documentation, literature etc) I can refer to support my cause, or is it ok in some situations to fasten through the ribs? |
Richard L Matteo, AIA, CSI, CCS
Senior Member
Username: rlmat
Post Number: 512
Registered: 10-2003
| | Posted on Tuesday, June 19, 2012 - 11:53 am: | |
Robin - I agree with you on the reduction of pull strength if they back-off on the fasteners and there is no way the "dimple" is going away if they do.
In addition to the local Building Code, look at the Metal Building Manufacturers Association (MBMA), the National Roofing Contractors Association (NRCA), and ASTM Standards E1514 (steel) & E1637 (aluminum) |
George A. Everding, AIA, CSI, CCS, CCCA
Senior Member
Username: geverding
Post Number: 630
Registered: 11-2004
| | Posted on Tuesday, June 19, 2012 - 12:51 pm: | |
What does the manufacturer say?
George A. Everding AIA CSI CCS CCCA
Ingersoll Rand Security Technologies
St. Louis, MO |
Robin E. Snyder
Senior Member
Username: robin
Post Number: 412
Registered: 08-2004
| | Posted on Tuesday, June 19, 2012 - 01:03 pm: | |
@George: Originally i spoke with a tech rep of the manufacturer and they said the fasteners should go through the flat part, but then they supposedly had a rep out at the site who didn't say anything and there appears to be a mysterious (questionable) relationship between the contractor and manufacturer, so I am trying to get some additional supporting data. |
George A. Everding, AIA, CSI, CCS, CCCA
Senior Member
Username: geverding
Post Number: 631
Registered: 11-2004
| | Posted on Tuesday, June 19, 2012 - 01:24 pm: | |
The silence could be due to the manufacturer and contractor trying to figure out the fix. By the way, for some residential metal roofs, nails are fastened through the rib, screws are fastened through the flat portion. We assume these are screws, right?
George A. Everding AIA CSI CCS CCCA
Ingersoll Rand Security Technologies
St. Louis, MO |
Robin E. Snyder
Senior Member
Username: robin
Post Number: 413
Registered: 08-2004
| | Posted on Tuesday, June 19, 2012 - 01:26 pm: | |
yes, screws. The contractor has asserted that he believes the fastening (through the ribs is correct) and the only solution he has offered is to loosen the fasteners to help "undimple" the metal. |
Tony Wolf, AIA, CCS, LEED-AP
Senior Member
Username: tony_wolf
Post Number: 36
Registered: 11-2007
| | Posted on Tuesday, June 19, 2012 - 02:36 pm: | |
The contractor's argument is that it's typical for the Rockies and similar conditions. Survey manufacturers, suppliers and installers in your area to see if it's typical, and whether dimpling is typically acceptable. His arguments seem ludicrous, but maybe he's right. If it's not commonly accepted practice, how will he answer that? |
Wayne Yancey
Senior Member
Username: wayne_yancey
Post Number: 529
Registered: 01-2008
| | Posted on Tuesday, June 19, 2012 - 02:40 pm: | |
The contractors reason is bovine scattology. Exposed fasteners are always in the valleys. |
Liz O'Sullivan
Senior Member
Username: liz_osullivan
Post Number: 59
Registered: 10-2011
| | Posted on Tuesday, June 19, 2012 - 03:00 pm: | |
I think that where panels lap, fasteners go wherever they lap, which is often in the high part, but then the rest of the fasteners usually go in the valley. But some manufacturers' literature for some exposed fastener panels shows some screws in the ribs. For example, http://www.metalsales.us.com/files/ctrs/architectural/5V-Crimp%20CTR%202012.pdf I'll email you with a local rep's name for one manufacturer. |
Don Harris CSI, CCS, CCCA, AIA
Senior Member
Username: don_harris
Post Number: 265
Registered: 03-2003
| | Posted on Tuesday, June 19, 2012 - 04:45 pm: | |
Never seen fastening through the ribs, always on the flat. It seems to me that pulling back on the screws will probably allow water infiltration. I can't see the dimples popping back flat, either. |
Joseph Berchenko
Senior Member
Username: josephberchenko
Post Number: 33
Registered: 08-2003
| | Posted on Tuesday, June 19, 2012 - 04:59 pm: | |
Exposed fasteners can go in either the "high" or "low" corrugations. Depends on the panel.
Joseph Berchenko AIA CSI CCS
Assistant Director of Architectural Specifications
ARCOM |
Paul Gerber
Senior Member
Username: paulgerber
Post Number: 133
Registered: 04-2010
| | Posted on Wednesday, June 20, 2012 - 01:02 am: | |
I agree with Wayne...I'm calling BS too.
To my way of thinking (and of course that may be the biggest flaw in my argument), any structural connection to the substrate should be at the low part of the sheet. If the roofing system doesn't have an interlocking seam design where the panels overlap, then smaller gauge sheet metal screws could be used to hold the 2 panels together (but I would also hope there would be a bead of sealant run down this joint before it is screwed together). With the structural connection at the rib, there is NO WAY the roofer is going to be able to ease up with the screwgun/impact wrench before the rib is "dimpled" (I think crushed would be a better descriptor).
And I wholeheartedly agree that the fasteners should NOT be backed off for the previously stated non-popping characteristic of metal and because it will undoubtedly allow water to infiltrate (however if you go by the premise that ALL metal roofs will leak and you have provided a waterproofing membrane at the deck/substrate level this wouldn't be as catastrophic as it would be in the absence of the membrane...and IMHO if the roofer installed the fasteners through the rib, there's not a snowballs chance in H E Double Hockey Sticks there is a waterproofing membrane below the metal)
Liz, I would hope that for the structural fastenings the manufacturer's guide spec would call for something a little beefier than a #9 wood screw. My metal roof and siding spec sections call for delegated design of the system including girt gauge (we give them the depth and spacing), fastener size and frequency in order to resist snow and or wind loading per Code. That's not my bag tyvm and I don't want anyone getting hurt/maimed/killed when siding/roofing panels blew off because I couldn't use my calculator one day or I didn't think about changing some values from what was in my master spec section!
Ride it like you stole it!!! |
Liz O'Sullivan
Senior Member
Username: liz_osullivan
Post Number: 60
Registered: 10-2011
| | Posted on Wednesday, June 20, 2012 - 01:24 am: | |
Hmmm. Yeah, maybe that was not a good example. |
Joseph Berchenko
Senior Member
Username: josephberchenko
Post Number: 34
Registered: 08-2003
| | Posted on Wednesday, June 20, 2012 - 11:20 am: | |
Most commonly it's in the valley, but not always. Here's another example. Look at page 6. http://www.aepspan.com/files/MetalBldgSystemInstallMarch06_MetalBldgSystemInstall.pdf For wall application AEP Span recommends valley fastners for Nu-Wave Corrugated; for roofs they recommend through high point for same panel type.
Joseph Berchenko AIA CSI CCS
Assistant Director of Architectural Specifications
ARCOM |
George A. Everding, AIA, CSI, CCS, CCCA
Senior Member
Username: geverding
Post Number: 632
Registered: 11-2004
| | Posted on Wednesday, June 20, 2012 - 02:37 pm: | |
The high point recommendation (roof vs. siding) may have to do with keeping the fastener out of the drainage path?
George A. Everding AIA CSI CCS CCCA
Ingersoll Rand Security Technologies
St. Louis, MO |
Joseph Berchenko
Senior Member
Username: josephberchenko
Post Number: 35
Registered: 08-2003
| | Posted on Wednesday, June 20, 2012 - 03:39 pm: | |
Yes, historically that was the issue prior to weather-sealing washered screws. Not sure why manufacturers engineer their panels one way or the other now. However, a look at the manufacturer's installation instructions for the product in question would be better than speculating on the issue here.
Joseph Berchenko AIA CSI CCS
Assistant Director of Architectural Specifications
ARCOM |
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