Identifying Open Web Steel Joist circa 1982 1

[charliealphabravo]

I am preparing for a site inspection where I hope to identify an open web steel bar joist (Alberta, CAN).

I just want to make sure that I collect enough information, on the joists in particular, so that I can identify/verify them, or find them in an old catalog, or reverse engineer if necessary, the capacity for a proposed set of rolling library shelves.

In short, can I expect to find a manufacturer's name or other identification on the joists or should I plan to measure everything with a tape and caliper?

Just for context, the construction drawings show the system as:
125mm (5 inch) slab
150mm x150 mm (6x6) - p35/p35 WWR
38mm (1.5in) x 0.762mm (22ga) steel deck
406mm (16in) deep OWSJ @ 1000mm (~40in) o.c.
spanning 6000mm (~19'8")

The loading was specified as
LL = 3.83 kN/m (263 plf) (~80psf)
TL = 7.42 kN/m (510 plf) (~155psf)

Thanks in advance.

 

[JAE]

Joist manufacturer's many times leave light metal tags on one end of the joist - wired on - which you can get project numbers, joist marks identifications as possibly even standard joist sizes.

 

[MiketheEngineer]

JAE is right and you might get lucky... Or it might have mfg number and you might contact. Some of them kept pretty records. SJI (steeljoist.org) has a book that goes back like 80 years - but it is mostly (maybe all) Imperial.

The also have a Web based software program that might help??

Is there a Canadian SJI??

Looking in the book =- seems like it may be 16H6 - no guarantees. BTW- it is rated fro a Total Load of 520 - no mention of Live Load.

Good Luck

 

[BAretired]

Measuring the members will not tell you the grade of steel used. If web members are closed tubes, you won't be able to measure thickness.

I would assume that existing joists are capable of carrying the specified load but no more. None of these guys put a lot of fat in their designs.

BA

 

[charliealphabravo]

Here is a photo of the joist. Even though the plans are metric I think the joists are Imperial.

I have a call in to SJI to pick up the updated publications. Anyone have any experience with their CD/DVD library? It would be nice not to have to lug around my old wire bound manuals.

16" deep joist
3/4" bar
3-1/4" wide bottom chord
7 gauge chord steel (4.44mm)

 

[charliealphabravo]

oops, missed the attachment.

 

[gte447f]

I don't think that is an SJI member joist, but I could be wrong. I can't tell from the photo... are the chords double angles, or some non-standard shape?

It is probably best to do as BAretired suggests and assume they will support the specified loads only. You are lucky to have the specified loads, many times you don't even get that.

Otherwise you will be faced with measuring EVERYTHING (the welds are usually the most difficult) and analyzing, and even then, as BAretired pointed out, you will not know the grade of steel. It is very tedious.

 

[charliealphabravo]

Understood,

The chords are not double angels, they are an odd hat-channel-type shape...angles i mean

Just for posterity I spoke with Ken Charles at SJI. SJI has a joist investigation service that you can initiate from their website, free I think he said it was but i could be wrong.

Also if you want to get all their publications digitally you can order: 80 Years of OWSJ Construction package for $75, download the free 43rd Edition Spec, and download the 8 Technical Digests for $160.

 

[paddingtongreen]

It used to be that you ordered a certain joist but they could make it any way that worked, usually it depended on the cheapest material at the time. They often used the hat sections for the chords and bent rods for the diagonals. I think none of that steel was high strength.

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[BAretired]

The joist you show in the photo appears to be a Great West Steel (GWS) joist with 'hat' sections for chords.



BA

 

[BAretired]

For some of the properties of the GWS joist, see the following link:

thread507-279859

BA