Not a happy camper…Just as I’m finishing a $10,000 deck, I read (JLC) that ACQ pressure-treatment chemicals may cause accelerated corrosion of galvanized steel.
Both ACQ and CCA are still available in my area, but I thought I’d be progressive and go with the ACQ. As a reward, I get to worry that all the galvanized nails, joist hangers, post bases and invisible fasteners will rust through in no time.
But I’m not worried! I’m sure our friends in the federal government that demanded the change from CCA will be there to help me!
Seriously, though, has anyone observed this reported accelerated corrosion?
Al Mollitor, Sharon MA
Replies
Sorry buddy, but I think this whole thing with replacing CCA is going to be a fiasco until they get it all sorted out. Probably take 5 years or more. And I think the galvi metal thing will be just one of several probs...
Guess I'm just not a cutting edge kind of guy when it comes to building materials. Just my worthless opinion...
And yes, I saw the JLC article too.
Perhaps someone else will be along to verify this shortly.....
But the news that I've read is truly bad. I seem to remember someone here at BT, who went back to an ACQ deck about 6 months after building it. Only to find that most of the nails were already worthless from rust.
Stainless nails and screws are painfully expsensive, but in this case, you need them.
You hear right. From the liability standpoint, go fix it before it gives you a bigger headache. Decks built last summer are falling right of the houses this year around here. All the galvanized stuff is shot. Not just the nails and screws. 1/2" lags are shot. Post bases are just little piles of orange dust. And yeah, stainless isn't cheap. A little box of finish nails (1200 ct) for my Senco cost $47. A small box (100 ct) of deck screws $8. Senco and some others are getting with the game at least and making more fasteners available in stainless. I am told this fall Senco will have most of their wares available in stainless, from framing to finish nails to collated screws.
"The child is grown / The dream is gone / And I have become / Comfortably numb " lyrics by Roger Waters
A lot of "interesting" ino out there:
http://www.strongtie.com/ii_General_Corrosion_Info.html
Testing has shown that stainless steel fasteners, anchors, and connectors corrode substantially less than other alternatives when used with ACQ-C and CA-B treated wood. Simpson recommends use of stainless steel fasteners, anchors and connectors with treated wood when possible. At a minimum, customers should use ZMAX¯, Batch/Post Hot-Dip Galvanized or mechanically galvanized (per ASTM B695, Class 40 or greater) product with the new chemically treated woods.
http://www.treatedwood.com/products/preserve/useofmetalspreserve.pdf
Results from standard accelerated corrosion tests for ACQ treated wood are similar to CCA, ACZA, and CBA treated wood with electroplated and hot-dip galvanized metals.
http://www.hoffmanestates.com/PressReleases/PR-NewLumber.pdf
The Village’s Code Enforcement Division advises persons considering projects that require the use of lumber to note a unique characteristic of ACQ/AC2-treated lumber. Specifically, ACQ/AC2-treated lumber must be used with only hot-dipped-galvanized or stainless steel hardware. The reason: The chemical composition of ACQ/AC2 reacts poorly with typical galvanized hardware and, over time, could contribute to the structural failure of a constructed item.
http://www.osmose.com/acrobat/NaturewoodFastenerInfoSheet.pdf
_______________________
http://www.medic37.net/prayer.shtml
Your mileage may vary ....
I read that just yesterday after getting a $4000 check for work with same product.
Now, I'm going back with stainless to refasten and an apology to the customer who doesn't know it yet. There is a brochure adressing this at the lumberyard that says that you'll be fine as long as you use hot dipped but these experiences reported here are disconcerting.
But it proves one of the values of the web and these sort of info sharing sites. I don't need to wait five years and a couple hundred thousand dollars worth of liabilities before I find out - or worse, an injured customer.
Excellence is its own reward!
Have many of you all been seeing much of the new PT lumber? Is it the ACQ "flavor"? Are the HD gal joist hangers, etc, becomming redily available in your area?
There is a blurb in the new JLC related they show a good detail, where joist hangers are protected by putting 15# felt between the wood and the joist hanger - a bit of a PIA, but not really too bad.Matt
Since the Indians and Chinese have been flooding the market with stainless steel, at OEM pricing I can get 18-8 (304) stainless screws at prices cheaper than I can get electrogalvanized screws at the local big box store. They're square drive, quite strong, and available in both flat and pan heads- the only disadvantage is that the cheap ones are all-threaded (i.e. with no unthreaded shank) so you have to drill a pilot. Bolts are quite reasonable too. Not much call for stainless nails for industrial uses, so they're less common and hence more expensive.
I was at Home Depot a few weeks ago and the Simpson Strongtie guy was there replacing all the hangers, etc. with their heavier Z-Max stuff. They are aware and concerned about the corrosion problem.
Al Mollitor, Sharon MA
WE just removed ACQ .060 "Naturewoood" (from Osmose) 6x6 posts for new second level deck (to be waterproofed) after only being up for three weeks because the nonZ-MAX abu66's from Simpson were already pitting and rusting. Granted these were not Z-MAX but three weeks !! I'm afraid that Z-MAX (twice as thick galv) would maybe have made it six weeks.
I haven't seen or heard of any here in central Illinois.
The lumber yard I frequent had no idea when they might start getting some in.No matter how good she looks, some other guy is sick and tired of putting up with her
I went thru the local yard yesterday, and they are stocked to the sky with CCA.
So I am guuessing it will be awhile before we see anything different here.View Image
I was in HD today, and two managers were discussing the mis- match of their treated lumber vs fastening hardware. One said he had been told that "regular decking screws and nails have failed in 6 months". They also did not have any electro gal foundation anchor bolts, but did say the coated aluminum flashing was ok, but not the bare. Wonder how many DIY decks come down over the next year or two...PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home
Thanks guys. The big boxes around here have neither the ACQ or the HD hangers. Lumber yard has both CCA and ACQ, but not the hangers, however they say they are getting some in, but I doubt there is a big rush on the ACQ, since it is more $. Matt
It won't be just the DIYers who have problems.
I built a high end roof top deck, building the room under it as well and used PT with regular hangers. It's all enclosed and dry, but in the middle of the night, I sometimes wake and sweat a little.
My insurance company knows about it.
BTW, my HD has 2 sets of hangers, regular & Z-max. Finally. After I've been at them for 3 months. Their answer is, if you & the insurance company sue us, we"ll sue the lumber manufacturere.
SighQuality repairs for your home.
Aaron the HandymanVancouver, Canada
This certainly is quite a revolting development and it hasn't even hit the main media yet. Waiting for a story reporting all on the evening news. Then 'a vanishing suppy of old pressure-treated lumber mysteriously occurs'.
It got me thinking if maybe I should go stockpile what I need for a future deck seeing some places don't carry any arsenic pressure treated lumber on their racks anymore at all.
And the other places couldn't give me an answer as to how long they'll still be receiving the stuff.
Makes me wonder if deckbuilders might be altering their future deck grid designs so as to use less hangers and hardware. I mean deterioration in months and weeks and gasket scenarios is scary stuff.
Will any arsenic PT still be made available for ground contact as in a pole barn frame or is this going to be a total elimination?
It's about time for someone to start bashing politics for all this. I mean they NEED to address this issue too. Maybe it's a subliminal terrorist attack of some sort.
'Police today arrested individuals in a suspected meth lab ring in Middle of the Woods, Tennessee only to discover a complex still making moonshine, a large amount of 3 gal. toilets imported from mexico along with huge cargo containers and tanks being used to manufacture arsenic based pressure-treated lumber.' News at 5.
Edited 1/15/2004 8:48:41 AM ET by rez
>>Makes me wonder if deckbuilders might be altering their future deck grid designs so as to use less hangers and hardware. <<
I have always preferred using ledger strips rather than hangers since it's faster and cheaper. And, with 8 or so toenails, maybe a few face nails, and then the 3 nails in the ledger, it's just as strong, especially since many of the hangers only have 4 toenails that hold the joist to the ledger. The problem is though, your still using nails that have a ?? lifetime in this new ACQ wood.
>> Will any arsenic PT still be made available for ground contact as in a pole barn frame or is this going to be a total elimination?<<
I think I read somewhere that the CCA will still be produced for farm and industrial use, but so what, if you can't find it easily.
Really, I don't necessarily blame the EPA and the government though. The government is not mandating ACQ - their just banning CCA. I blame the tree huggers who wanted to get rid of CCA based on gossip and some isolated inconclusive evidence. Really, they got to realize that if their kids eat several #s of the stuff and die it's simply natural selection ;-). And I blame the PT wood industry for not starting to test the alternatives products exhaustively 5 years ago when the ban was eminent. I mean maybe they tested the wood samples under some laboratory conditions, but it doesn't sound like they really actually built much of anything out of it...Matt
Time to brush up on your mortise and tenon skills. Start stockpiling those wooden pegs. Every deck board will now be a sliding dovetail.
Who wants to be the first to feature and patent a no artificial fastener deck design?
"Who wants to be the first to feature and patent a no artificial fastener deck design?"
I already did that. I call it a "patio."
I continue to worry about ACQ. As far as I know, most places around here have made the switch from CCA to ACQ. I know HD has and the Simpson fastener section has warning signs about corrosion. I thought January 1, 2004 was the official change-over date.
On the plus side, a local small lumber yard here has been selling ACQ for several years now and they seem quite unaware of any problems. It seems like they would have had some complaints by now if it was as bad as we fear.
Al Mollitor, Sharon MA
Al Mollitor, Sharon MA
Every deck board will now be a sliding dovetail.
Did that for floor joists in my outbuilding with rough cut 2x's. Building inspector had no idea and left shaking her head. 12 yrs later they're working just fine. Slightly more time consuming than joist hangers.PAHS Designer/Builder- Bury it!
Just out of curiousity...
Why???
Was it exposed?
Jon Blakemore
Just out of curiousity...
Why???
Was it exposed?
It was/is exposed. That wasn't the reason, however. I didn't really know how else to do it. Could have reduced the joist ends to fit into a normal hanger, but I figured if I was going that far I might as well have fun. A large router, a big bit, a template and a LOT of chips flying. Feels great to walk on.
I'm not much of a carpenter so I built both post&beam buildings here more like furniture, with dovetails for most joints. (Attachment)
As for the sliding dovetails, the first ones I made, many years ago, were for a guy who wanted a backless cabinet able to hold 8 lineal feet of LP albums with no support under the shelf. He didn't think I could do it. The look on his face when I loaded it up was priceless. It was all suspended from the attic trusses. Dovetails, gooooood joint.PAHS Designer/Builder- Bury it!
More! More!
.
More! More!
More dovetails? Or what? Got the copper for the roof in and need more rafters, but before that I need my crane to lift my, um, er, ah, unusual cupola up there. I'm sloooooow. And those bones have got to be covered soon. Been out in the weather for way too long now. Everybody wants to know if it's recycled timber.PAHS Designer/Builder- Bury it!
I'm afraid to check back to see the previous messages for fear I'll lose the site again. She is a fragile woman tonight.
.
Japanese did it centuries ago, and many of those castles and temples are still standing. They did not use any treated lumber.
BTW why did they ever require the use of treated lumber in the first place? I can maybe understand the ground contact part, but masonary contact I don't.
You control the enviroment and the pest, and treated lumber is sometime over kill.
Dave
>>I can maybe understand the ground contact part, but masonary contact I don't.<<
Any cementous material in inherently damp. And it wicks moisture up. So, wood in contact with concrete, bricks, block, etc rots. Ever notice that the part of a post that is sitting on concrete that rots first is the post bottom. That's why we use those metal post feet.Matt
Any cementous material in inherently damp. And it wicks moisture up.
I see no evidence of that in our underground concrete house. My head building inspector told me that he'd never recommend concrete for the whole house. Asked why, he said they were always wet. He didn't know why. That was until he came back here a few years later. Now he's recommending concrete. It's not an issue as long as you control humidity. Without controlling humidity you get condensation.
Requirement was for pt wood touching the concrete. I did the trim after CO inspection and it all touches concrete. No problem 12 yrs later, even with a wood that isn't particularly rot resistant (hickory), including next to our slab floor. But we have no condensation on the concrete.PAHS Designer/Builder- Bury it!
tom.. don't be committing the onerous deal of applying your specific results as a universal truth..
concrete and block walls WILL wick moisture .. the tests all prove it... and capillary action can accelerate it.... any contact of a dry, untreated, framing member with a concrete wall in contact with the ground .. with no cappillary break , can result in rotted framing and a good invitation to termites and carpenter ants..
if you have a peculiar condition , or have done something else to remove the moisture.. that's fine.. for most wall systems.. both a capillary break and a treated sill are called for
but hey ,whadda i no ?Mike Smith Rhode Island : Design / Build / Repair / Restore
I think we agree.
Maybe inherently damp was not the best choice of words. Lets go with: "intermittently damp when part of the cementous assembly is in contact with a moisture source - in the case of a foundation, it's the soil." or, as you say humidity. I got to assume that your underground concrete structure is pretty well isolated from the soil. A foundation, which is what I was referring to is sitting right on the soil. Matt
I think we agree.
Maybe inherently damp was not the best choice of words. Lets go with: "intermittently damp when part of the cementous assembly is in contact with a moisture source - in the case of a foundation, it's the soil."
Mostly. Thanks for the clarification, Matt. Our house, though, is directly in ground contact for better than 4000 sq ft altogether, not at all isolated. That's the only way the heating/cooling "system" will work. Clearly cement products, most especially block, can transfer moisture. What I was trying to point out is they don't have to. That's the design part. We have dry dirt on the outside, by design. Not a topographic curiosity either, we have a hill rising behind the house that drains this way.
Our head inspector isn't now going around telling everyone that concrete solves all problems, especially after all the wetness he's seen/sees. What he is doing is telling people to give me a call to find out how to do it. It's not complicated. A good friend, a gc (formerly concrete suspicious), is planning something similar to ours. He currently has a basement tenant who suffers from a leaky foundation with wet dirt outside. She is also interested in building, but can't bring herself to even consider anything with dirt on the other side of the wall. Her loss.
Regarding cement products, it also is worth noting that boats, work great constructed of ferrocement. Waterproof is dependent on the water ratio of the mix. But that's not something you can get from a readymix truck. PAHS Designer/Builder- Bury it!
Tom:
One of the things that the prefab concrete Superior Walls people advertise is that their 5000 PSI concrete is waterproof, but their nailer studs are treated... An interesting contrast... Their wall panels are are poured and cured in a factory setting though, which would probably be hard to replicate on a building site.
Anyway, are you saying that the concrete in your below ground home is waterproof - I think the spec is 4400 PSI min; you have no damp proofing, etc on the exterior side of these walls? I visited your web site some time ago, and seem to remember some poly sheeting or something was included in the design - can't quite remember. Would you mind posting the URL?
Aside from that, in keeping in the context the main topic of this thread; PT wood, wood that is in contact with masonry or concrete must be protected by some means from rot - weather that be by flashing, pt lumber, or some other kind of capillary break. A number of years ago, they used tarpaper. How many postings have we seen here with questions relating to rotted mud sills on older homes? Admittedly my experience is limited to building in VA and NC, and homes built in the arid Great Plain states, and SW are probably much less prone to rot problems. Wood rot is tied largely to moisture, and I have seen those old ghost towns in the SW desert areas that seem frozen in time. Matt
Hey Matt,
Superior Walls is outside my experience. My concrete only needed 3000 psi to keep the engineer happy. Waterproof it's not, and my only, small, point is that it isn't wicking or otherwise transmitting moisture. My walls and roof are a variety of experiments ranging from bentonite waterproofing to bare dirt. All work just fine. Clearly the bentonite was a waste of $1500 (material only), which my client chose to forego. He placed a sheet of 6 mil poly against the carpet he put next to the concrete. Carpet to maybe keep the poly from tearing on the concrete. It was primarily for the backfilling and to keep the concrete dry(er) until the umbrella was constructed. It's the umbrella that keeps everything under it dry. His house leaked until we got the umbrella installed. While his wife just about drove me nuts worrying about it. Then she thought me a genius (clearly wrong) when the leaks stopped. Extends out 20' from the perimeter, consisting of 6 mil poly encapsulating xps. An excerpt from the book I more-or-less followed is at:
http://www.axwoodfarm.com/PAHS/UmbrellaHouse.html
I haven't forgotten the pt point. I used pt here to keep the inspector happy and certainly I didn't know any better. Not certain I do now, but my wood trim in contact with concrete, neither pt nor particularly rot resistant, is doing just fine. The reason, the bldg. inspector explained, was because concrete is "always" wet. Simply ain't so, as he happily found out. The difference is between "can" wick moisture and "will" wick moisture. Mine "can", but "won't". This can be replicated just about anywhere.
My experience is also mainly Va, with distant memories of Arizona and Denver, both with little wood rot problem, although my childhood home in Arizona had the interior wood trim completely eaten by termites coming up through the slab on grade. Probably in the interior studs too but that was a future owners' problem. Fortunately home inspections are a little more complete than they used to be.
We've also seen many posts here about the ease with which poplar will rot if used outside. It can, but doesn't have to, witness Monticello. Again, back to good design. As much as I love wood, I don't consider it any better material for house building than TJ did. Bug food. Pt solves most of that, but brings in some new problems, like disposal. And apparently ACQ is going to be a windfall for hardware mfgs. My windows here are poplar with some oil splashed on occasionally, certainly no rot. Also no standing water. You're absolutely right about wood rot being tied to moisture. I have no problem directing that moisture away from my wood here. Wood deck? No, I'll stick with concrete. I've also seen pt wood that didn't last. Little faith in "permanent" wood foundations, particularly in wet locations. I'm sure you've also seen successful century or two old houses and looked to see how they were assembled. I don't buy Mike's argument about old growth wood being the ticket. I've looked at the comparable annual rings. But it's going to be a long time before my stuff will have passed that test of time, if it makes it. What I can say is my wood products have shown no rot degradation, considerably outlasting the competition. Particularly the exterior planters.
When I've had an application where wood will stay wet, I've been successful with white oak, walnut, or black locust. Exterior shutters, for example, where I wouldn't use poplar due to the design. Actually, the local cedar is far more rot resistant. Fence posts still sound 75 yrs later. None growing here and I haven't bothered to acquire any. PAHS Designer/Builder- Bury it!
In 1976 I tore down a framed garage that was 34 years old. It was sitting on 8" concrete block that were laid on a shallow concrete footing. The interior was a crushed cinder floor. No gutter and no special exterior grade treatment. The whole thing was being pushed over by two large trees planted on one side of it. I think the only thing keeping it erect were the tree branches draped over and through parts of the roof. City building inspector said it had to go.
I thought it woud be an easy take down , even by hand. This was an all volunter job by the local JayCees, as part of the 76 bi-centenial beautifcation of an inner city block. Two days of hard work later we got it down. Even though we could break the block foundation wall loose with sledge hammers, we had to break individual blocks to tare out the bottom plates. All the framing was rough sawn oak . Siding was red wood and roof sheating was 1x6 pine.
There were areas of rot for sure, but no termite damage (luck), but over all the thing was pretty sound. There was not a piece of treated lumber in the thing. The treated back porch of the house on the property had to be rebuilt. It was only five years old,poorly built and maintained, but what shocked me was the amount of rot in the framing lumber. Bad treatment, bad construction, poor design, and a host of other things could have contributed to its' early demise. I did not know enough about building back then to even guess about it.
Two structures, fifty feet apart. One well built, but not maintained, with no treated lumber lasted 34 years. If the maintenance and those darn trees had been taken care of, that garage would still be standing. The porch might have made it another five years with a lot of care.
As a rookie carpenter I learned what every one here pretty much preachs. The best materials can not makeup for poor design and construction.
I am coming to think that some of our current code requirements were written to cover just those problems :)
Dave
DaveRicheson writes:
The best materials can not makeup for poor design and construction.
I am coming to think that some of our current code requirements were written to cover just those problems :)
Bingo! Give that man a prize.PAHS Designer/Builder- Bury it!
No, the prize goes to this BT site.
I have learned as much, or maybe more here, than I ever learned just strapping my tools on every day.
Dave
Was it an open porch?Matt
If I remember correctly, that porch was exposed to the weather. The one next door was covered, but suffered nearly the same failure rate.
I have been under houses, porches, and decks that were not sitting on treated lumber. In the better built older homes, nothing was left to chance. Flashing details were followed fairly rigidly thoughout most of the homes of the late forties and early fifties. Even the lower end home had some sense of continuity within a developement. Treated lumber was unheard of, and yet I saw fewer failures in those home than I did in the homes of the mid seventies and early eighties, after the introduction of treated lumber.
It was as if many builders thought the stuff would save them from poor workmanship and bad design. Termite and pest control treatment also drastically changed durring that period. I think that is was gave birth to treated lumber, but it spawned a lot of bad building also. The first thing to go was termite shielding at the mud sill. Then came the selling of treated lumber as a maintenance free product. People and builders actually believed that for sevral years. By the time the truth crept out, the damaging forces had been at work for several years.
Homeowners and builders both knew that when you built a porch with standard KD lumber, it had to be protected. Painting was a routine maintenance chore, and standard construction. People either paid someone or did the upkeep themself.
Not so now. Everyone, including builders, wants a maintenance free home. In addition to that we also have developed a zeroe tolerance for anythig that might be bad for the enviroment or our health. While all that is admireable, we don't seem to recognize that there may be some mutaully unachievability with those goals unless the consumer is willing to pay for them.
What follows is manufacturers driving code changes, and the public buying into all the hype that surronds many new products.
All of the above is MHO. Take it for what you paid for it <G>
Dave
dave... i started in construction before PT lumber was available... our only recourse was creosote or cuprinol green #10.. and flashing .. and painting.. and caulking.. and proper construction techniques..
none of those was going to save modern style deck frames from rotting.. and we used splines on top of the framing too..
PT has changed all of that for the better... sure . bad workmanship can circumvent PT.. but please don't tell me that modern wood is the equivelent of old growth wood .. there is no way modern wood can stand up to the elements unless it is PTMike Smith Rhode Island : Design / Build / Repair / Restore
I have to agree with you on all counts, especially concerning old growth lumber vs. new lumber.
I don't mean to sound like I am kocking PT lumber, only the sorry building practices that seem to have evloved because of all of the hype surronding its durabilty.
I do mostly repair work now days, and a few building lay outs for one foundation guy and another builder. The things I see in repair work is the stuff left out because of the "it is treated lmber" syndrone.
Heck I even admit to following some of those practices myself. It was what I was learned from some of the builders I worked for or with. Even some of the inspectors here don't recognize what , strictly speaking, is a code violation.
Pressure treated mud sill with joist and band board (rim joist) sitting on top of them, followed by sheating board lapped over this and sitting dicectly on the foundation wall. If there is a brick drop, I have seen the sheathing setting down to the brick ledge. No flashing beneath, just tyvek covering the whole assembly. I probably won't be around when the rot eats ou the sheathing behin those brick veneers, but I have already repaired sheathing behind vinyl siding. Lots of other issue with those repairs, but I see a lot stuff that is product related. Of course most of it goes back to what someone is wiiling to pay for "fine home building."
IMO there are no "magic bullet" building products out there, and that includes PT lumber. You use the best that is available and design and detail your work to last. When something better comes along, you use it, but the design and detail remain the work horse of you building.
I have learned that from you and the people at BT, as well as real life experience.
Dave
Well ACQ PT lumber is finally in full use here in NC, and the correct fasteners and framing anchors are becoming more available.
What I have learned is that framing anchors should be ASTM-A653 rated and nails should be ASTM-A153.
Of coarse nothing is ever simple. I find that many of the HD gal nails are ASTM-A153 Class D. Class D.... ??? So I go and research that, it it looks like ASTM A153 class D means 1 oz on zinc per sq foot, and I think Class C is 1.5 oz of zinc per sq ft, and Class B is 2.0 oz of zinc per sq ft. Obviously Class D is the least desirable...
The nails I used to use were ASTM B117 rated, which is a salt spray rating, which may or may not have a bearing on how they react to ACQ and other PT chemicals.
Another recommendation I ran across is never mix dissimilar metals - ie HD joist hangers with stainless steel nails is not a good idea.
Just thought some of you would be interested in this stuff....Matt
I think I posted this before.... snagged a scrap of ACQ from a job, drove a couple dozen fasteners of all types into it including nailing on standard joist hangers with standard JH nails, also some stainless nails and screws, electrogalv, HD galv, bright steel, yellow screw, powder coated deck screw, etc. etc. One of everything I got, basically. A couple of weeks out in the elements and now in a the damp dark corner. Nothing happening that I can see. Very anticlimatic. Or is it anticlimactic?
Interesting.... let us know how it's comming along in several months.
Matt
I appreciated your real world approach to this seemingly big mystery (nobody will own up to anything) so much that I decided to emulate your test. One suggestion that I will make is you should try to find a scrap of CCA to use as a control group. I will be interested to find out what answers our testing gives us.
Jon Blakemore
I don't know how damp that damp corner is?
I am not sure, but I think that it needs to be in contact with water (rain). Also being exposed to the sun would also be more realistic. It will heat the piece up and sppeed up any chemical reaction.
I was doing some work plumbing work monday extending some copper lines. But along the run there was a copper nipple screwed into a galvanized steel elbow. It a touch of surface corrosion and that looked old. I almost left it, but decided to replace it with a dielectric union. When I removed it the elbow was 1/2 filled black deposites. When I screwed in the dielectric union and tested it was dripping. As I tightened it up the elbow cracked.
It looked ok on the surface, but where there was water the damage was being done.
Although it's a very good idea not to mix metals because of galvanic corrosion concerns, you can be a little less worried if stainless steel is one of the metals. In practice, stainless steel doesn't tend to behave as the noble material in galvanic couples as easily as you might predict. So I personally wouldn't be as concerned about zinc fasteners on stainless hangers, for instance.
Aaron, You live in beautiful country. Visited Victoria once, and loved it.
Let's hope the dry deck does not corrode the hangers.(??) Don't know if soaking the wood/hangers with wd-40 would help prolong the life. Do we know the expected life with Z-max?
A daisey chain of law suits would make only the lawyers happy. I told my local HD they need notices and to tell all customers who buy the new PT
the required hardware. The potential of major injury is in the making, if typical fasteners begin failing. I will speak to both Loewes and HD next week in Vegas, if I can find them, and if they are not swamped. PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home
You can't use it for fastners, but I know the reply about felt it could be substituted, I am using the roll roofing rubber membrane material between the new wood and flashings. At least until I run out of existing flashing and then it's all going to be copper if I can help it.