I’m a contractor who is – finally- commencing to build a home of my own. I get the plans back from the arch. and engineer with this big notation attached with regard to the hung 11 7/8 tgi’s at top of stemwalls. Apparently the Simpson hangers I have used forever are getting eaten up by whatever nasty stuff is in the pressure treated 2×6 mudsills. Their solution was to use 2x con common redwood sills and actually double them up so the plumbers/ electricans et al don’t resort to busting out any of the stem wall to swing supplies up into the wall lines. Anybody out there have alternate solutions or run into this apparently new rusting scene? A friend told me today there’s actually a big ol sign at Home Depot now basically saying don’t use hangers on p.t. wood- but not much else… I’m blown away as I have build miles of deck in just this fashion…what’s up???
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Few people understand it. Nobody agrees what it is, how to learn about it, or who's responsible for it. It has never been more important
Featured Video
Builder’s Advocate: An Interview With ViewrailHighlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
Z-Max from simpson is a line of metal parts/pcs ok to use with the new treated wood. Fasteners need be approved also.
Remodeling Contractor just outside the Glass City.
Quittin' Time
Check out this link for the info you need:
http://www.strongtie.com/productuse/corrosion.html?source=hppromo
There have been several discussions about this on Breaktime and articles in FHB and JLC. There is lots of concern about the new ACQ lumber and steel fasteners.
In your case, with the work being inside, there's probably less to worry about. Use the Simpson Z-Max hardware and real hot-dipped galvanized nails.
Al Mollitor, Sharon MA
Woody:
The new ACQ lumber is indeed far more corrosive due to the very high copper content. For the deck I'm building right now, I'm using the Simpson Zmax galvanized hangers because I couldn't find anyone making stainless hangers yet. However, I read an article from the US Forest Service that claims that painting the hangers can more than double the life of the metal in contact with this new PT stuff. So... For the cost of a few spray cans of paint and an extra hour of time, I painted all the hangers. I also found stainless joist hanger nails from Swan Secure. The price was steep but not awful.
Of course, hangers used indoors are safer than those used out in the weather.
J Painter
J.P.--what exactly is the trip with the corrosion? Even though I'm building inside my understanding is that the corrosion is due to the interface of the metal with the copper...more a chemical reaction than due to moisture...at that point I'm guestioning the connection with steel anchor bolts/ washers/ nails through wall plates into sills etc....actually thinking more of just blowing off the entire thing and putting con common redwood down as plates-readily available...and going with my old standbys, Simpson itt 11.88's. any thoughts? Woody
Woody:
The high copper content of ACQ means that reaction with metals like steel, aluminum and even galvanized steel is far more likely and more severe than with the old CCA stuff that had a lower copper content. Rain or moisture only accelerates the potential reaction.
Simpson rates their Zmax hangers specifically for ACQ because they have a heavier zinc coating on them. They use the same part number with a "Z" at the end. However, long term testing in the field has not really been done. That's why I painted for added protection.
I don't think you need to use redwood sills-- although maybe I'm biased due to my regional thinking. Here in the Northeast redwood is almost an exotic wood! If you use Zmax hangers and stainless nails and bolts you should be fine. I'm certain the metal connector industry will soon catch up with the new law and stainless hangers will become more common. The stainless nails and bolts are already commonly available, just a little more pricey.
J Painter
J,
You mentioned the stainless hanger nails from swan. Be sure not to mix those with the Z-Max hangers you are using. That's another fast-track to corrosion. Keep stainless with stainless and hot dipped galvy with the Z-max stuff. Also gotta remember not to use good 'ole aluminum roll flashing, as that too will deteriorate quickly when in contact with ACQ.
McFeely's has stainless hangers in their catalog and online if you're so inclined. I've read everything I can get my hands on regarding this new ACQ deal and I'm feeling relatively confident with using copper roll flashing, double hot dipped galvy fasteners, and Z-Max hardware. It's not breaking my bids either.
Diesel:
You know, I've heard some state what you did concerning the mixing of galvanized and stainless, and I've heard others directly contradict that. I dunno. I've never personally seen stainless have a problem with any other metal, but I'll tell you what: it would be nice if the building materials industry would get their act together and agree on something!
J Painter
I don't mean in any way to sound sarcastic........
Do a little research and you will find that under dry conditions the corrosion issue is almost a non issue.
Ask around and you will find that out. Big difference when something is exposed or not; you know that already.
Eric, good luck with the house.
"Dry" is a relative term however. Here in Florida, anything outside is "wet" because of the high humidity, even if it doesn't get direct moisture from rain, etc. Add salt air if you live near the coast and things are really bad. New Mexico or Arizona "dry" is quite a bit different.