No such thing as stoopid questions. Here code requires larger diameter nails for joist hangers (larger diameter than normal nail gun nails). Whats to be used in current pressure treated lumber if such larger diameter nails aren’t available double dipped?
Let’s not confuse the issue with facts!
Replies
To add to the questions I'll add one.
Lets, just for the sake of argument, say that someone produces the double coated nails for hangers used on ACQ. Further lets say you use these nails. My question is: What happens to this coating as the nail gets driven through the holes in the hanger? Wouldn't this damage the coating on the nail? Possibly the hanger?
I realize that galvanization 'heals', migrates onto exposed base metal, scratches but this is within the wood and in a corrosive environment.
Does this mean that stainless nails, being immune to corrosion even when scratched, will be the best choice?
Just bought some Bostich Triple Dipped. They are new. 10D's, maybe 12's. I'll check Thurs. AM.
Hhmmm. Dunno?
F.
Cheese me off, bought the Bostitch 2MCN thingie that places metal connector nails, now all the double dips are for 28* collation and mine is 21*. Is that called planned obsolence or niche marketing?Let's not confuse the issue with facts!
Time to back off the ACQ corrosion scare and really look at the big picture.
All you guys with the positive placement guns, all you guys with the palm nailers and all you guys using the manual method. WHERE ARE YOU USING TREATED MATERIAL?
All my rafters are ordinary yellow pine. So are my trusses, so are my top plates, so are my ceiling joists. As are my floor or rim joists and headers. No ACQ in my studs, either.
Maybe Doug Fir for a bunch of you. Maybe engineered products for some of us, too.
All my straps, hurricane clips, joist hangers, etc. will never come in contact with treated lumber.
SO, NO BIG DEAL.
My next project will have about 70LF of 2x8 ACQ Treated on a poured stem wall. Thats the only place where I have to be concerned about the fasteners contacting ACQ. I can deal with that. And, on a slab floor, with only the bottom plate treated, hand nailing super galvies there is also no big deal.
Deck building is another thread.
um, exterior decks?"If you pick up a starving dog and make him prosperous, he will not bite you. This is the principal difference between a dog and a man." - Mark Twain
To repeat my last line:
"Deck building is another thread."
Except for Bob "Pro-Dek", there are very few here that concentrate on exterior projects that might require a preponderance of treated material. I do think that almost all may have built one or more exterior decks and will probably build some more during their careers but IMHO most use treated lumber as a simple barrier in their main endeavor and the fasteners and connections are for the most part NOT in contact with or affected by the new ACQ treatment.
The post that prompted my response had to do with my perception of someone saying that his positive placement gun was obsolete (useless) because it wouldn't accommodate the different collation of galvanized nails. I would venture that 99% of his guns use is with NON-ACQ material. Therefore, no big deal.
Ralph, aren't your 3" X 6" mudsills ACQ? The foundation anchor bolts now have to be G-185 rated I believe.
Outside decks, well that is another subject. I've been really busy trying to make all these new components work with each other.
Simpson has the Zmax hardware but not the bolts, you can't mix stainless with galvanized because dissimilar metals corrode.
Fastenmaster ledger bolts have been approved as long as we use a 3/8" galvanized washer? there goes that dissimilar metal thing again.
Flashing has to be vinyl copper or stainless.
Deck screws have to be ACQ rated.
I've been losing bids to guys not smart enough to up their prices at least 14% for these new materials, but like I always say,
"I can stay home and not make any money."
"Rather be a hammer than a nail"
Bob
The word on ACQ sills is "isolation".
I don't use anchor bolts. SAY WHAT???
I use threaded rod all around the building to provide a continuous path from top plate to foundation. The rod is epoxied into the slab or stem wall after the framing is up. Holes are drilled through the plates and into the concrete, cleaned and then the epoxy is injected. When the rods are placed, some of the epoxy is forced up and out, coating the rods where they go through the treated plates. There's the isolation.
Sounds good to me...............
Ralph, If a deck is planed for a house do you bolt a treated ledger on where the deck is going?
Around here most builders just fasten the deck ledger over the Hardi plank like it was an after thought."Rather be a hammer than a nail"
Bob
Dennis raises a good point I hadn't considered:
http://forums.taunton.com/tp-breaktime/messages?msg=43048.10
His construction problems will be the same as those who build exterior decks.
Regarding the ledger: Yep. That's how a lot of them are done here. I've had to pull off a few to repair T1-11 siding and in one case the rot, with ants and termites, had gotten to the main framing.
My experience with decks is only with 5-6' or less off grade and all I do is build them free standing. That solves the connection problem to the house. I think that if I were to have the opportunity to build a really tall deck I would still have it free standing, but use 2-3-4 really large steel brackets attached to the house structure and flash those really well under the siding, thereby minimizing the number of penetrations while still stabilizing the deck.
So if you were to build a free standing deck tomorrow what would use for the bolts into the posts (structural and railing), framing nails, and deck screws?
Jon Blakemore
You gotta wonder about the people who claim that vinyl siding is a proper flashing material.
Jon Blakemore
as long as we use a 3/8" galvanized washer? there goes that dissimilar metal thing again
You could use a nylon washer to isolate the galvanized one. It's yet another added expense (for the knowledgable) to jump through the ACQ hoops. Just a thought for short-term fix.Occupational hazard of my occupation not being around (sorry Bubba)
Re: "Simpson has the Zmax hardware but not the bolts, you can't mix stainless with galvanized because dissimilar metals corrode. "
This might not be a significant problem. It depends on a lot of factors. IMO the major ones are : Moisture, chemical environment, anodic differential or the specific components and alloys used, cathode/ anode ratio and the possible use of a third, or fourth anodic element.
Moisture. A lack of moisture to create the electrolytic solution would preclude galvanic action. Also true of the simple corrosion between the ACQ and the hanger. It occurs to me that perhaps a few simple design changes might provide some degree of cover from rain to limit both problems. Perhaps arranging a wide board to be directly above the hangers or maybe a small non-metallic roof. Something as simple as a flap of tar paper concealed by the deck might be effective.
The chemical environment. Being as that we are assuming the use of ACQ you may not have much control over this aspect. As has been noted not all ACQ treated lumber is the same. While you would want .40 concentration for ground contact a lighter concentration might be cheaper and could be beneficial in reducing corrosion and the electrolytic environment that causes galvanic corrosion. Idea being the less ACQ devolved in any water washing down over the hardware the better.
Anodic differential. As noted in the below table metals differ in their anodic potential. The greater the differential the faster the galvanic corrosion.
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The relevant lines are: Zinc (galvanizing), steel (the structure of the hanger and galvanized nails), stainless steel ( 300 or 400 series depending on the components used).
The cathode/anode ratio, C/A. The effective ratio of surface area between the two, or more, engaged in a galvanic reaction. The idea being that in these reactions the component with the highest anodic rating becomes the anode while all others effectively become cathodes. It is the anode that is dissolved while the cathode remains largely untouched.
On to the ratio. The effect seen on the anode is distributed along its entire effected surface. This means that a high C/A, a large cathode and a small anode concentrates the galvanic action on the small anode. Example being a steel screw installed on a copper plate would cause the smaller screw to dissolve very rapidly. The same materials reversed, a steel plate and a copper screw, would be less an issue as the galvanic action of the copper on the steel would be distributed over the exposed surface of the steel plate.
More than one galvanic component. This is seen in boats. Typically you see aluminum alloys, copper, bronze and stainless on boats. All exposed to seawater. In this case you would expect to see massive galvanic corrosion on any exposed aluminum as it is the the most anodic of the metals involved. The reason that this doesn't occur, barring poor maintenance, is that most boats use heavy zinc plates bolted to the hull. These are called zincs or sacrificial zincs.
The idea is that as long as the zinc is the most reactive metal any galvanic corrosion will be taken out of them preferentially. This is why they are thick and heavy. They have to be to last and it is important they last because when they run out the next in the series takes the wear.
How does this relate to stainless steel nails in a zinc coated hanger? Back through the list.
Moisture. Galvanic corrosion only happen when wet. Deck hangers could be expected to drain and dry in some environments. The corrosion would stop when the components dry out. Maybe less in Seattle but a good thing in Arizona.
Chemical environment. Using less heavily treated wood above hangers where possible.
Anodic differential. Use 400 series stainless, a bit cheaper but less corrosion resistant, instead of 300 series. Counter intuitive to use less resistant stainless but it keeps the differential smaller so less wear onthe zinc galvanization.
C/A ratio. In this stack the stainless would be the cathode and the zinc coating the anode. Also remember that only the heads of the stainless nails would be in play as the body of the nail would be encased in wood and fairly well protected. This alone would lead me to believe that stainless nails would be much less a problem than might be assumed.
Third components. Zinc is pretty high on the anode stack so your choices of metals you could add would be short. Magnesium being the only choice. I don't think I would add magnesium. Magnesium is almost twice as reactive as the zinc and tends to disappear quickly. You could likely see it disappear day by day and it would have to be replaced.
The only thing I can think of along these lines would be to perhaps bolster the available amount of zinc, the steel would only be exposed when the zinc runs out, by adding some zinc sheeting, available as moss preventative for roofs. This would need to come into firm electrical contact with the hanger in the spot most likely to be wet. Perhaps bent over the top edge of the hanger as it is nailed into place.
I was reading the article and thought of this picture I found in Taunton's new Decks and Outdoor Projects mag.
Makes me want to use stainless for everything. Taunton should put this on the website too.
gk
Gabe:
Hadn't seen that one. Thanks.
All:
What does mechanically galvanized mean? Is it better or worse than electroplated?
Thanks.Matt
If I'm not mistaken (big if ;) ) it means the nails are "tumbled" with the galvanizing material as opposed to it being plated on. From what I recall it is rated as a relatively poor way to galvanize... but ummmm don't quote me on that ;) I oughta ask my father who is a metallurgist but I'm not up for a lecture on galvanization ;)
You have it right, but I don't know which is best. I am thinking that the mechanical is as it has a slightly thinker coating.
But none of them are as good as hot dipped.
Well again, this is just from my memory which may not be accurate but I believe that mechanical is lowest, then electroplated, then hot double dipped (I seem to recall that just hot dipped wasn't rated all that well) But I have a feeling others out there are better informed than I am. I actually was just looking at the Swan website http://www.swansecure.com to check out their line of SS nails to see what they offered for hanger nailing, looks like they've covered all the basics.
My understanding is that hangers for ACQ lumber are now required to be triple coated. The ones I've been supplied with are electro-galvanized and and are stamped accordingly. Nails need to be coated similarly. If you have problems with finding the proper nails or hangers, contact your hanger manufacturer. Around here it's Cant Sag or Simpson. Your lumber supplier should be aware of the corosion issues with ACQ and have the proper hangers and nails, (though they may not be available for you pneumatic guns), if they don't have what you need, tell them to get it for you or go to a lumber yard that knows it's stuff.
Woody
Damn pricy but Swan has stainless collated nails and many hanger styles. I imagine others do as well, seems to me that if you build it into the price of the job it's cheap insurance.
Paul,
Great theory....but not very useful in the real world. Go price out the cost to build an average deck using stainless nails, carriage bolts, lags, and hangers. Now go try to sell one to the average person. You'll lose 99% of the jobs you bid.
LOLLLL, OK OK I'm trying to make the switch here from engineer to contractor :S Is there a position open for board theoretician? I keep thinking of the plumber (Vincent Gardenia?) in that movie "Moonstruck" (I know chick flick but he was a great character). "There's three kinds of pipe..." great scene if you haven't seen it.
Paul
" stainless nails, carriage bolts, lags, and hangers. Now go try to sell one to the average person. You'll lose 99% of the jobs you bid."
That's why I put up that picture of the nails...show that to your homeowner and then try to sell them. I thought it was quite thought provoking and influential. Along the lines of, "sure, I'll use galv. nails but hold on to my card so I can come back in 5-10 years to build you another deck."
In related news, I helped on a public boardwald project last year. The city's prints called for .60 treated lumber and +3" nails but never specified a nail coating. The guy I was helping wanted to use bright....I told him to get stainless or hot galv. He got a couple boxes of galv then started to buy bright because the galv was too expensive for him and the city inspector could care less. I quit and told him to never tell anyone that I had helped.
who knows when it's gonna fall down now.
gk
Seems I recall when I was in a shop that made hydraulic couplings for aircraft..we anodized alum. onto titanium parts..and nickle plated load beams for choppers..they were steel, with a coating of Nickle
So, if aircraft bolts and such are Titanium, why would that not work too? More $?????
The boss handed me a bolt about 3/8 x 4 and a hacksaw..said go cut this in half at the vise...after a few passes I looked at the blade...no teeth! I thought he was messin with my teenage brain, so I put in a new blade...4 swipes and teeth gone..neat stuff to play with!
http://www.titaniumfinishing.com
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Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Titanium is bigggggg bucks... try pricing that into a deck ;)
looks like gutter spikes for everything then..lol
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Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
So is it true that the ACQ corrosion is not a problem if there is no moisture? Or do we have to go around and hotdip toenail all ther studs we unthinkingly attached with sinkers to the ACQ plate? Nobody even thought about it, even though we'd just built a big old deck, using only hotdipped. iIncidentally, I can testify to the corrosive power of ACQ - after one day of decking in shorts (yes I am stupid) , I had a dime-size hole eaten in each knee....was it the years of using the arsenic stuff that made me this dumb?
Titanium would be a far more expensive and more prone to galvanic corrosion than either 300 or 400 series stainless.
Remember that the metal we are most concerned about is the zinc coating of the hangers. The zinc is more anodic than anything else in the series except magnesium. This means that the zinc will be the anode and take the abuse, dissolve first.
Go back to that table.
Zinc -.90 to -1.03400 SS -.20 to -.35300 SS 0.0 to -.15Ti +.60 to -.05
As you can see the 400 series stainless is much closer to zinc in potential than titanium. So it would be better to use stainless as either would keep difference much smaller. The best choice of the three would be 400SS.
The other thing is while stainless nails, particularly for nailguns, are rarer and more expensive titanium nails, of any sort are in particularly short supply.
I sent Paslode an email about this issue, and got the following response, hopefully it's accurate...
<Response (Kirsten) - 05/10/04 08:57 AM
Thank you for contacting Paslode
Paslode Positive Placement nails are safe for use with ACQ.
Please see the attachment for fastener information>
There ummm was no attachment :S
Pondering what's left of my memory from the mid sixties when I sat through a lot of chem classes..........and.......
The chart you gave us was for seawater...a salt solution galvanic reaction chart.
What happens to those values when used in ACQ....alkaline copper quaternary?
What is the chemical formula for ACQ?
Does the extra corrosiveness of ACQ come from the "alkaline" factor contributing a heavy dose of hydroxile ions to react with the metals of the fasteners?
What is the ionization constant for ACQ? This will effect the rate of corrosion.
Just lots of questions........Iron Helix
There is an ACQ Material Safety Data Sheet which gives the percentages of different compounds in ACQ at:
http://www.ufpinc.com/literature/acqmsds-200.pdf
Some stuff on fasteners (haven't checked to see if these have already been referenced in this thread):
http://www.treatedwood.com/fastener.pdf
http://www.naturalselect.com/corrosionposition.pdf
Edited 5/13/2004 4:14 pm ET by CaseyR
I used sea water because it is a well understood and researched environment. It is also a fairly rough environment so I was thinking that results might be closer to what is seen, based on anecdotal evidence, with ACQ. As to how all this will work out with ACQ in the long run is antibodies guess but the general chemical principles should hold.
Yeah, an theres a good chance most of Fla. will be under seawater..when the "big one" comes..
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Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Always good to know that your deck, even covered with 30' of water, is still standing proudly. I suppose that given enough warning, and a few changes to the decks design, you might be able to disconnect the deck from the house and sail away from the water disaster in fine form. Kind of a 'castaway' option for the house. Givent he average elevation in Florida this might be, as Martha Stewart says, 'A good thing'.
I'd go with the co2 inflatable pontoons..LOL
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Spheramid Enterprises Architectural Woodworks
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Thanks to CasyR for the MSDS sheet.
Thanks to 4Lorn1 for the seawater table....it set me investigating. (For what it's worth...if anything.----we need a full blown chemist.)
Same safety hazards for a carpenter as was the CCA......Take precautions. Inhalation and skin absorption are the greatest threat.
The CCA of last year was a copper and arsenic complex....the new ACQ is a complexed Quaternary Copper and ammonium compound. Similar chemical packaging...different chemicals.
AS far as the ACQ chemical composition.......to the best of my "old" knowledge!
There is an organic "monoethanolamine" compound that I think is for mold/fungus control--------0.80 to 5.5 percent
Then there is the Copper complex, expressed as Copper Oxides----0.30 to 2.1 percent. This is the Quaternary Component of the ACQ. The workhorse of the designed chemical mix.
Boric Acid----0.20 to 1.02 percent for control of insect infestation.
Alkyl dimethyl benzyl ammonium chloride-----0.20 to 1.0 percent.
Didecyl dimethyl ammonium chloride----0.20 to 1.0 percent.
Both of the ammonium compunds are used as a stabilizer for the copper complex.
The ACQ part of the formula mix is listed as a Proprietary ingredient---their "secret ingredients. But if you look up copper or ammonium compounds you will find a compound called Tetraamminecopper II...it is produced by dissolving copper hydoxide in liquid ammonia to form a very strong base.(read as--CORROSIVE)
The issue of fastener degradation may not be with galvanic reaction as discussed above,but simply that the ACQ is a strongly basic compond capable of corrosion.
Most of our real world experiences deal with corrosion with acids...due to the obvious "bubbly and stinky" reaction of battery accid with just about every thing it touches.
The base chemicals are just as strong, but don't exhibit the visual side. The most common base household chemical is lye or draino....lots of damage, no fizz.
In conclusion (maybe wrong) the problem with fasteners in ACQ is not necessarily galvanic as much as it is corrosive. Draino does okay in stainless sinks, but don't let it set in a galvanzied bucket.
Iron nails/fastners with a zinc coating in damp or wet ACQ wood will undergo a continual chemical dissolving reaction......how quickly will the posted "nail corrossion" picture be the reality of ACQ fasteners applied today. It will be a lot shorter than 14 years.
Caustic compounds are usually hauled in Stainless tankers....not galvanized steel.
IMHO----use SS where ever possible, because the coated steel products will corrode away with time.
SS nails @ $5 lb......SS hangers, singles 2x10 @$7 ea.....SS 4x4 post base @ $56 ea
I'm considering going back to ss Nailing the joist as in the days before hangers, adding the triple galvanized hangers, knowing that as they may corrode away at least there will be some margin of safety between visual inspections.
Tough call...................Iron Helix
DUDE! are you some kind metallurgist or chemistry major?
At any rate, no one is paying me to study the deteriation factoids of bolts,nuts and nails. I'll leave that one to the experts.
I just want to go the the lumber store and have them supply me with all the right stuff.
Good information 4lorn, but my eyelids started to fall before the end of your post.
"Rather be a hammer than a nail"
Bob
Let's get 4lorn to be our alchemist and we can go on a lead standard...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
Hmm. Maybe I can try to shorten my prose and punch it up a little. Maybe some swimsuit models:
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Tossed around for decoration.On the up side your insomnia is cured. You looked like you could use some sleep.
Good Morning Ralph:
In answer to your question...."WHERE ARE YOU USING TREATED MATERIAL?"
FYI down here in the Islands (Bahamas), ALL structural timbers used in construction are pressure treated, so ALL of our metal hardware and fasteners are in direct contact with this stuff.
Usually the only non-treated wood products used are doors, cabinets and trim.
"Time to back off the ACQ corrosion scare and really look at the big picture. "
So at least for some of us, this issue is a major part of the "big picture".
Dennis