Floor beams max span table question for Canadian building code

[vcm80]

I have been obsessed over a structural question to which I cannot find any clear answer. When calculating a built-up floor beams with the code tables in part 9, there are tables for beams supporting no more than 1, 2 or 3 floors. Does that mean that I simply count the number of floors over that beam? That's what I always did but a few colleagues have been arguing that you only use the tables for 2 or 3 floors if there is supporting walls over that beam and not other floors supported by other beams. Is there any source of information that specifically explain the answer?

 

[KootK]

I think that I'm with your colleagues on this one. Those bearing walls over the beam being considered are how the load from the upper floors gets to the beam being considered. If you have matching beams at all floors, the lower beam is not supporting the upper floors, except, in end bearing.

 

[vcm80]

I think that I'm with your colleagues on this one. Those bearing walls over the beam being considered are how the load from the upper floors gets to the beam being considered. If you have matching beams at all floors, the lower beam is not supporting the upper floors, except, in end bearing.

Structurally speaking I agree. What I find hard to believe is that its not clearly stated in the building code. Things are usually clearly specified and I feel that if it's the case it let too much interpretation.

 

[KootK]

You might enjoy perusing a copy of the International Residential Code (US). They pretty much have all the same stuff as we do but, in many cases, it's been expounded upon to a greater degree. Lots of diagrams and things.

 

[XR250]

I suppose you could calculate it manually.