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

RE: Unfamiliar bar joists

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Title: RE: Unfamiliar bar joists
Butler has a similar cold formed joist called a "Truss Purlin."  Their overall depth is 20-1/2" or 29-1/2".  The chords are shaped similarly to the described shape but are a little narrower (5-1/4" wide excluding lips, and 1-1/4" deep)... however the end seat is around 7" wide and together with the top chord usually is 9-1/2" deep although a 2-1/2" version is available.  The web members are hollow round cold formed sections which are "pinched" and welded at the joints to the chords.  The thickness of the chord seems to be in the ball park of what our chords might be.  We don't call the chords sombreros and generally don't refer to a gage thickness (usually decimal inches).  I am not familiar with the 40 JS designation either.  With those differences, it doesn't sound like a Butler Truss Purlin.  Unfortunately I don't have any additional information to help you figure out who the manufacturer was.
 
Good luck!
Greg Effland, P.E.
KC MO
-----Original Message-----
From: Brian K. Smith [mailto:smithegr(--nospam--at)bellsouth.net]
Sent: Friday, June 29, 2001 12:35 PM
To: seaint(--nospam--at)seaint.org
Subject: RE: Unfamiliar bar joists

The metal building industry ("pre-engineered") are using something very similar to these now.  I know Butler has some.  If the building is only a couple of years old, surely you can find the fabrictor and ask them some questions.
 
Brian K. Smith, P.E.
-----Original Message-----
From: Adair, Joel [mailto:JAdair(--nospam--at)Halff.com]
Sent: Friday, June 29, 2001 10:10 AM
To: 'seaint(--nospam--at)seaint.org'
Subject: RE: Unfamiliar bar joists

These joists are only a couple of years old.

The joist seats are made by adding an additional "sombrero" section, inverted.

-- Joel


-----Original Message-----
From: Davis Parsons [mailto:dparsons(--nospam--at)msc-engineers.com]
Sent: Friday, June 29, 2001 9:51 AM
To: seaint(--nospam--at)seaint.org
Subject: Re: Unfamiliar bar joists


"Adair, Joel" wrote:

> We have a project in Reynosa, Mexico that involves adding some framing to an
> existing building.  The existing framing uses some joists that we are
> unfamiliar with, and we wanted to find out if someone might have an idea who
> the possible manufacturer might have been.  The joists are designated "40
> JS" on the plans.  The chord members (called "sombreros" on the plans) look
> like cold-formed light gauge sections with a configuration like this (pardon
> the ASCII art):
>
>      ___
> |___/   \___|
>
> They are designated "cal. 14", which we understand is 14-gauge.  They are
> 0.18 m (7 inches) wide and 0.03 m (1-3/16") deep.
>
> The web members are made of continuous bar stock bent into a normal joist
> web configuration, and welded to the chords at the bend.
>
> Anyone have any information on these joists?  Who would be a possible
> supplier or manufacturer?

That type of chord section was used in joists made by Truscon, Bethlehem, and
Armco.  None of the old catalogs that I have show a chord width at 7 inches.

What year range were these joists produced?

Are the joist seats made with just an inverted piece of chord material or do
they have a piece of flat plate attached?

--
Davis G. Parsons II, PE RA AEI
a practical structural engineer
in Fort Worth, Texas