Bare Steel Nails in Interior PT Lumber.

[XR250]

Got a call about a new construction house where PT lumber was used as joists in the crawlspace (the wrong lumber was sent). Framers used standard framing nails.
House is just finished and the home inspector picked noticed it. Is there any precedence for this being OK?

 

[jayrod12]

As far as I'm aware, standard nails/screws will degrade due to the chemicals used for the treatment. However my memory may be thinking of the old treatment chemicals, not the new. Last I saw in one of the canadian standards is either Hot-Dipped Galvanized or stainless steel are the only acceptable fasteners. But that was for preserved wood foundations, where the cost to remedy a failing fastener is substantial.

 

[Enable]

It depends on the type of treatment. Anything with copper is a no-go but I believe treatment with Borates or (the old style) CCA is compatible with regular steel nails (the Canadian Wood Council explicitly says as much, see second link below). Though your governing code may be based on all copper treatments and have a blanket statement to the effect of "only galv or stainless fasteners to be used with PT lumber"

Borates

CCA, MCA and Others by CWC

EDIT - If you're using the IRC I think you might be in luck (second attempt) if borate treated and the crawlspace is inside the building envelope.

 

[phamENG]

Best bet is to have them provide the data on the preservative that was used. The manufacturer of the chemicals should tell you what fasteners are compatible.

 

[Eng16080]

There could also be an issue if there are non-galvanized joist hangers in contact with the PT wood.

If the crawl space will be well-ventilated and dry, the potential degradation should be slower.

 

[XR250]

Thanks for the info, Y'all. I am not going to get too involved in this one as it is a no win for me. Any future floor squeaks and I'm getting sued. I told the customer I would spend a few minutes poking around the internet though.

 

[jerseyshore]

There could also be an issue if there are non-galvanized joist hangers in contact with the PT wood.

This is purely anecdotal based on building my own house and stopping at a multitude of Home Depot's, Lowes, & lumberyards, but it's almost impossible to find non-Zmax Simpson products these days. I think you'd have to go out of your way to order the plain galvanized ones.

So I'm less concerned about hangers in contact with PT wood, but I would not approve any standard Teco nail in PT wood. Asking for trouble. Smart to pass XR.

 

[lexpatrie]

I'd try Woodworks.

I thought there was some fine print about Borate preservatives having to stay dry to avoid corroding fasteners. (I know it's for decay resistance when wet, I know), so it was for interior use only, so putting it into a crawlspace, well, maybe. If I recall correctly they are not viable as sill plates on the first floor of a building where they are in contact with concrete. Somebody should confirm the vapor retarder and the crawlspace ventilation are appropriate as well (not "us").

 

[dik]

Depends on the treatment... with some PWF material, anything short of SS or HDG is not likely going to last.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Eng16080]

This is purely anecdotal based on building my own house and stopping at a multitude of Home Depot's, Lowes, & lumberyards, but it's almost impossible to find non-Zmax Simpson products these days.

I just did a quick google search for "Home Depot Lus28" which brought me to the product "LUS Galvanized Face-Mount Joist Hanger for 2x8 Nominal Lumber" on home depot's website. According to the product listing, it's G90 galvanized, but according to a comment from a Simpson rep. in the Q/A section it's not rated for contact with PT lumber:

"The LUS28 hanger is intended for an interior dry installation and not in contact with pressure treated lumber. We also make the LUS28Z. Z-stands for our premium Zmax finish that is suitable for a medium corrosive environment such as most pressure treated lumber chemicals and fresh water (rain) exposure."

I always call out this connector as "LUS28Z" on my plans where it's in contact with PT, and "LUS28" elsewhere.

On the HD website it's also not at all clear, without doing a bunch of digging, that this product should not be used in contact with PT nor outside. There's even a picture of it being used for what appears to be a 2nd floor exterior deck. Wtf! I'll bet that lots and lots of builders and especially DIYers are incorrectly installing these in contact with PT thinking that it's ok since it is (minimally) galvanized. I can picture a construction manager telling the new guy to pick up some galv. joist hangers for the new deck they're working on, and getting these.

 

[lexpatrie]

Pressure Preservative treatments vary, both in the amount of chemical used and the chemical itself. The general desire for heavier galvanizing is for the outdoor rated PPTs. Borate isn't outdoor rated. I wouldn't absolutely rule out Borate preservative treatment on a "normal" joist hanger. In construction defect, you need to prove there's a problem via (at least) documentation, research reports, in the product acceptance line, you're supposed to prove it will work, based on research reports, etc. (See IBC 104.11)

The contractor, ultimately, is the designer of record on a lot of decks, without being explicitly licensed to do design, but the product selection is on them when they function as the designer of record, as well as code compliance. Compliance with the specifications, when they exist, is on them as well.

Their ignorance, negligence, or skill, depending on the case, is their own. Starting work constitutes acceptance, etc. etc.

 

[jerseyshore]

In all of the HD's/ Lowes' around here they only stock Zmax hangers, even tho the website is a little ambiguous as you found out. Seeing an LUS and not an LUSZ hanger in the wild is extremely rare from my experience, but like I said, that is purely anecdotal. I'm sure the next house I go to will have rusty LUS hangers all over.

 

[Eng16080]

jerseyshore, That has been my past experience as well, but I figured I'd check the website, and once I did, I wasn't sure if they perhaps changed what they offer in the store. In any case, it seems that it would at least not be impossible for somebody to get the non Zmax connectors.

Next time I'm in HD, I'll have to check.

 

[Eng16080]

To follow-up with my previous post, I was in Home Depot today and as far as I could tell, every Simpson connector in stock has the Z-Max coating. Good call on that jerseyshore.

 

[jerseyshore]

 

[phamENG]

Since when do GIFs work on this site?

 

[jerseyshore]

Since they upgraded it to the 19th century. Wait until reply's with quotes are added, our heads will explode.

 

[Eng16080]