trim coil over pressure treated wood?? - Contractor Talk - Professional Construction and Remodeling Forum

Lt.H · 04-11-2006, 04:02 PM

With all the issues over the pressure treated wood, can you use trim coil to wrap pressure treated wood? And if this is allowed, is there a "special" type of nail that has to be used?

bob the builder · 04-11-2006, 05:02 PM

Aluminum should not be in direct contact with acq. Some sort of barrier should be used to seperate the 2...

Bob

marc · 04-11-2006, 05:18 PM

We build You need to use a painted coil though......NOT pvc coated because the back of it is raw aluminum and the PT will eat right through it. I've seen it with my own 2 eyes. We have never had trouble with the painted coil though..........been doing it since 1997

bob the builder · 04-11-2006, 05:53 PM

Quote:

Originally Posted by marc

We build You need to use a painted coil though......NOT pvc coated because the back of it is raw aluminum and the PT will eat right through it. I've seen it with my own 2 eyes. We have never had trouble with the painted coil though..........been doing it since 1997

Have you been using acq since 1997? Because acq has been determined to be around 5 times as corrosive as cca. Though it may be true that painted aluminum is acceptabe, it hasn't been adopted as such. I know that protrim http://www.alumapole.com/product.asp?ID=57&nPage=2 is "approved" for direct contact with acq.

I guess if painting aluminum is acceptable builders wouldn't be purchasing copper at 6$ a sq. ft.

1/4" spacer is recommended between aluminum and acq, poly 10 mil. is also suggested as other alternatives. Rubberized coatings were used in my state to solve the dilema on all the highway signs that fell off because of aluminum and acq...

Bob

marc · 04-12-2006, 06:31 AM

What you didn't see in my last post is that we build pre-fab aluminum Sunrooms.
To be honest with you...........I don't have a clue what your talking about when you mention ACQ or CCA.
All I can tell you is that we haven't had any problems in the last 9 years (that I know about) with painted aluminum coil on PT wood. We have had issues with PVC coated aluminum coil.

IHI · 04-12-2006, 07:06 AM

While I have'nt tried it yet, a fw suplliers stated wrapping 2 layers of building paper of the treated lumber will be enough barrier to protect the aluminum. We've always used painted stainless steel trim nails so that's not a problem.

I get to drop $1K out of my pocket for new aluminum siding around the base of a porch we did front treated lumber last year...big ole spores and burn through holes all over the place

N.E.Bldg&Rest.LLC · 04-12-2006, 08:40 AM

The company that makes Grace ice & water shield makes a thinner version for PT lumber. You can use it anywhere metal makes contact with the ACQ lumber like joist hangers, corner brackets, post holders etc, etc.
It's recommended to always make a barrier between metal and ACQ and to use stainless steel fasteners.
I could swear I read somewhere that ACQ is so corrosive that Simpson won't guarantee their Z-MAX line, But don't quote me on that.

Sider' Brian · 04-13-2006, 11:12 PM

"With all the issues over the pressure treated wood, can you use trim coil to wrap pressure treated wood?"

Not directly.
However, on a couple owner's request we have wrapped plastic around the pressure treated lumber and the use trim coil with no issues to date.