| Author |
Message |
Robin E. Snyder
Senior Member
Username: robin
Post Number: 588
Registered: 08-2004
| | Posted on Saturday, May 09, 2015 - 12:42 pm: |    |
I have an architect who is fastening stainless steel perforated metal sheet directly to the underside of steel deck (the stainless steel sheet is the decorative ceiling). This is an exterior patio along CA coast. A couple of questions (1) what is the best way to separate the metal deck from the stainless (washers, or prime paint on the bottom of the deck?) If washers, then what material? How do I specify the fasteners (assuming stainless, but how to i protect them against corrosion from the steel deck) |
Steve Pirozzi, CSI, CDT
Senior Member
Username: spirozzi
Post Number: 11
Registered: 12-2006
| | Posted on Saturday, May 09, 2015 - 01:58 pm: | |
http://www.euro-inox.org/pdf/build/Erection/ErectionInstallation_EN.pdf |
Dave Metzger
Senior Member
Username: davemetzger
Post Number: 576
Registered: 07-2001
| | Posted on Saturday, May 09, 2015 - 04:03 pm: | |
Robin,
This is not your question, but because of the coastal location I recommend that the stainless steel sheet and also the fasteners be Type 316 stainless. |
Michael Chusid, RA FCSI CCS
Senior Member
Username: michael_chusid
Post Number: 30
Registered: 10-2003
| | Posted on Saturday, May 09, 2015 - 05:19 pm: | |
An article I wrote for Construction Specifier may help" http://www.kenilworth.com/publications/cs/de/200808/files/64.html.
For fasteners, see take a look at the "Flex" products by Elco Construction Products: http://www.elcoconstruction.com/Products/Flex-Technology/Metal. They have good corrosion resistance properties and are self-drilling.
Michael Chusid, RA FCSI CCS
www.chusid.com www.buildingproduct.guru |
Justatim
Senior Member
Username: justatim
Post Number: 71
Registered: 04-2010
| | Posted on Monday, May 11, 2015 - 08:34 am: | |
The weak link I see in this assembly is the steel deck, which effectively will be exposed (through holes in the perforated SST) to coastal, salt-laden air, depending on how close the property is to the "coast." For this decking, I'd get the heaviest galvanizing available.
Stainless steel fasteners do not need protection from steel decking; however, the reverse is true.
I agree with Dave that Alloy 316 is appropriate for both the fasteners and perforated SST. Other readily available SST alloys will develop surface rust in coastal atmospheres.
As to the washers, which is a good approach, I'd consider only dialectic materials such as neoprene or nylon. |
Greta Eckhardt
Senior Member
Username: gretaeckhardt
Post Number: 8
Registered: 08-2013
| | Posted on Monday, May 11, 2015 - 09:53 am: | |
I think one other consideration is to make sure the detailing does not allow water to penetrate and remain in cracks and crevices. One of the most recent Construction Specifiers has an article by Catherin Houska, who is a very well-informed authority on stainless steel, and I recommend that you contact her or at least look for articles she has written. |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 900
Registered: 12-2006
| | Posted on Monday, May 11, 2015 - 10:26 am: | |
I've heard that using spacers can actually make the situation worse as that can now create an arcing condition that can accelerate the deterioration of the steel deck below.
While galvanizing is advised for typical conditions it will not provide protection against galvanic action between galvanized steel and stainless steel (go figure). Back when we were still poisoning the environment we could use chromate coatings on the steel deck to prevent galvanic action. Now there is some question as to what currently available coatings actually provide that level of protection. Unfortunately, I can't offer that information as I don't know.
The obvious problem with using coatings is that even if an appropriate coating is available corrosion can still occur in areas where the coating is scratched or not applied in sufficient thickness. I have seen similar applications where roofing felts were applied to the steel deck using bitumen (hot or cold applied) which formed an effective barrier to galvanic action. To my knowledge, this has stood up rather well.
Here is another good source for info:
http://www.nickelinstitute.org/~/Media/Files/TechnicalLiterature/11024%20GUIDELINES%20FOR%20CORROSION%20PREVENTION.pdf#page=1 |
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