We just switched our lumber suppliers and the new company is using MCQ PT instead of the Copper Azole that the last one sent out.
After doing a little digging, I’m finding that the claim is made that MCQ can be used in contact with aluminum (which we will likely not do) and that it’s LESS corrosive than CCA, certainly well under the virulence of ACQ.
Anybody with real world experience?
Here’s a technical bulletin from UFP.
http://www.ufpi.com/literature/pwtechbulletin-332.pdf
Simpson has another bulletin, but it doesn’t really say much.
http://www.strongtie.com/ftp/bulletins/T-PTWOOD08.pdf
Any thoughts?
Replies
bump
John,
I posted about this material in September 2007. It arrived at the local HD under the name of "ProWood" and is exactly the UFPI product you mention. MCQ.
I have a fastener corrosion test underway since 9/07. Test samples incorporate mill finish, aluminum flashing in direct contact with the wood.
Used KD, ACQ and ProWood as my test wood samples - one interior exposure and one exterior exposure.
More to follow - seems like there is some interest on the forum at this time - must be the summertime deck building season.
Jim
Edited 7/5/2008 5:53 pm ET by JTC1
Jim,Found this thread while searching about copper azole. Our local yard has just switched from ACQ to copper azole.Got any generalizations you can make yet about your testing?Steve
Steve,
Thanks for the memory jog. Will have to pull some fasteners this weekend.
Then will get back to all.
Judging based solely on exposed sections of fasteners, I see exactly what I would expect ---- "brights" are getting pretty furry with rust, all others, HD galvanized, coated screws, GRK's, SS are all looking great. But of course it's what's hidden that counts!
Jim
Never underestimate the value of a sharp pencil or good light.
I'll be really curious. I've pulled a few coated screws out of some treated sills recently...not sure what treatment, but there was very little of the screws left when I took them out, and they haven't been there more than about 5 years I would say.I've taken to using only stainless fasteners in treated, but there a few things I framed with ACQ last year and used hot dipped galvanized that gnaw at the back of my mind. Steve
Jon,
We used MCQ on a project ealier this spring. Above grade. I questioned the lumber yard that it was .15 rather than .25 that they carried for above grade in ACQ. I was told less treatment is required for an above grade rating.
We used Paslode HDG ringshank with an ACQ rating. I can't say re corrosion because it was all a non-structural application on some raised gardens.
Do you think it is about time for decks built (not using the proper hangers and fasteners) after January 2004 to start failing? I do.
Thanx for those links. Very informative.
Chuck S
Edited 7/5/2008 9:25 pm ET by stevent1