Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Tack Welds

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Title: RE: Tack Welds

Rick (and Casey, too):

Consider a situation where several bays of roof collapse in two adjacent five-year-old warehouses during a thunderstorm that arguably produced "fastest mile" winds of only 65 mph (UBC-91 code winds are 70 mph).  The roofs have very little dead load, with only a polyisocyanurate insulation board and single-ply EPDM membrane over a 22 gage wide-rib steel roof deck.  It is alleged that the open-web steel roof joists failed in buckling caused by wind uplift.  Now, consider what the uplift resistance might be if the lower chords of the roof joists were not laterally braced by the lines of bridging (nil, nada, zero).  That is why the tack welds have become very important!

Stan R. Caldwell, P.E.
Sweating in Sunny, Sticky Dallas

¤º°`°º¤ø,¸¸,ø¤º°`°º¤ø¤º°`°º¤ø,¸¸,ø¤º°`°º¤ø¤º°`°º¤ø,¸¸,ø¤º°`°º¤

-----Original Message-----
From: Rick Burch [mailto:rburch(--nospam--at)conterra.com]
Sent: Sunday, June 22, 2003 7:40 PM
To: seaint(--nospam--at)seaint.org
Subject: Re: Tack Welds


Stan,
Am I understanding correctly, that this case is about the welds of joist bridging to the joist chords?  I never thought about this being a serious source of liability before, so I would be interested in hearing more. On a lot of jobs I visit during construction, the joist bridging is not even anchored at the ends until I write it up in my site visit report, but I never thought of paying much attention to the welds of the bridging angles to the joist chords until you mentioned this case.

I know that in lawsuits, one issue can cause the original problem and then the lawyers hire engineers to scrutinize everything and collateral issues get brought in. Was this the case here? It's hard to imagine a $4.3 million lawsuit solely about joist bridging.

Rick Burch
Columba, SC