Old steel section 1

[Lutfi]

Okay, this one is for the senior engineers and the ones who are familiar with 1945 practices.

I am doing some renovation work to a building that was designed circa 1945. The roof trusses only have the loads on them (graphically analyzed!!). The room has 10"BJ15# joists. The roof is a bulb tee with gypsum. The best I can tell the bulb tee is 2.5 inches and it spans 6.92 feet.

I have few questions:

1. Where can i find properties for 10"BJ15# joists?
2. When the bulb tee is 2.5 and will span 6.92 feet, the data that I have says that the maximum total load is 35 PSF. Does this include the live load and dead load?
3. The engineer did not size the truss members. Was it normal practice for engineers to rely on fabricators to size the truss and welding? I thought engineers done it all back then.

I appreciate your input.

Best Regards,
Lutfi

 

[JAE]

From AISC's "Iron and Steel Beams - 1873 to 1952":

depth = 10.00"
Wt/ft = 15.0 lb/ft
Area = 4.40 sq. in.
bf = 4.000 in.
tw = 0.230 in.
flange thickness at root (m) = 0.269"
flange thickness at tip = 0.269"
Radius at web/flange intersection (R) = 0.30"
Ix = 68.8 in^4
Sx = 13.8 in^3
rx = 3.95 in
Iy = 2.79 in^4
Sy = 1.39 in^3
ry = 0.80 in.

This shape is listed as milled by the Carnegie Steel Company in 1939, by the Carnegie-Illinois Steel Co. in 1940, 1946, and 1948, and by the Illinois Steel Co. in 1934.

I would highly recommend that you get this book from AISC as it is very handy when working with old buildings and shapes.

http://www.aisc.org

 

[Lutfi]

Thanks a bunch JAE.

 

[MikeDB]

Is this an I beam or a bar joist?

 

[Lutfi]

It is an I section to the best I can see on the 1945 faded plans.