Paper Calmenson & CO. joist load table

joemarch
I am not familiar with your joist manufacturer. Suggest you obtain the depth and angle sizes and calculate the section modulus. Determine the approximate age of the joist and determine the yield stress of the steel. Use the allowable stress and figure the load per foot it can carry. Be conservative. Use engineering judgement to determine if that is reasonable for your span and loads.

Also, you might try the Historic Joist Catalog from the Steel Joist Institute. I don't know if it lists by manufacturer, but it might help you out.

Do you know the date of manufacture? If so, in addition to waht fepc says above (which I have done many times myself), you could figure out the weight in lbs/ft. Then from a load chart (like in historic catalog) you could cross reference your calcs to a published value. Just make sure you correct for allowable stress.