Cap plates on HSS columns for weather protection 3

[bnickeson]

Ran into a first today. We got a call from a contractor that discovered that several feet of water had gotten inside the HSS columns as the fabricator had omitted the cap plates on several of them. Many of these columns already had drywall around them, so they've got to do a bit of work and re-work to adequately drain them and get everything buttoned up again. He is looking for any written requirement or codification that he can use as recourse against the fabricator as I assume they're going to try and recoup the cost from them. Does anyone know if cap plates are a requirement on HSS columns and, if not, if they require weep holes if a cap is not applied?

I did some looking but couldn't find anything in AISC or online.

Thanks.

 

[bnickeson]

Possibly. But Section M2 is titled "Fabrication" so...

 

[Enable]

Possibly. But Section M2 is titled "Fabrication" so...

I think what XR250 is suggesting is that the wording is not "AND otherwise protected" but "OR otherwise protected", which means only one or the other is necessary under the standard. Since no drain holes were provided on the shop drawings (I imagine?) the fabricator could say "duh...you were supposed to protect them as you knew there were no cap plates / drain holes on the shop drawings...remember GC, the ones you reviewed? I just put up the steel you are required for all temporary measures. It's your site remember!"

But obviously at the end of the day it depends on standard practice in the locale, and as XR250 said, this seems very small in the scheme of construction costs. In such cases legal action is usually a fool's errand. Probably what will happen is the GC will hold the stat holdback or conjure up a deficiency holdback if the sub hasn't been paid yet, and if they have, meh.

Anyways, all very annoying. I think we've all learned just to specify cap plates / drain holes / protection measures in our general notes and let the others deal with it after that.

 

[dik]

It's the fabricator's responsibility?

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

-Dik

 

[canwesteng]

The economy of HSS columns vs wide flange depends a lot on the connections to them. Good choice for single story though.

 

[lexpatrie]

Here's the reference for completeness.

AISC 360-16 Specification

 

[jerseyshore]

I mean how hard is it to drill a hole and let the water out? On all of my HSS column details I have a note about providing closure plates, but I'm sure it doesn't happen all the time.

Also, if the columns have drywall on them, how did the rain get into the columns only, but not damage the drywall? Was water just pooling in there since the last rain? Sounds like a GC problem to me. If I was the fabricator I'd tell him to get lost.

 

[lexpatrie]

Pretty difficult to drill a hole inside the HSS through the base plate once it's erected, set, got the grout pad and has been enclosed.

To me this is a lot like stability plates at the columns for open web steel joists and/or joist girders, while these are erection aids and fabricator tidbits, I'd rather show the ones I know about on a standard drawing, make it clear these are a courtesy (in the general notes and remain the responsibility of others) so the drawings are more "finished."

If the fabricator doesn't provide them, well, the GC did get a chance to review the shop drawings before fabrication, and either they accepted it, indicating they were going to keep the thing dry, or they failed to mark it up. It would be better in the defense if the fabricator specifically called out the lack of a drain hole for the GC to confirm/accept with a cloud. Or just provide it, and if the drawing comes back with it crossed out, you know who made that decision.

As a side note, I tracked this provision back to the 2005 AISC 360. It's perhaps in the 1997 HSS specification but I didn't find a searchable version of that and I didn't see it in the 1989 Specification. So this is perhaps a lurking issue for folks to be aware of.

The situation I had with one (not my design) was an HSS in a pool area, base concealed from view, it eventually rusted out (from the inside?) and crunched down leading to say 2" of collapse. It had "Tube Steel" designations on it, but I don't know when exactly the plans were dated (my notes say 1984 construction). Happened in 2015.

So it's not a purely academic question.