Beam math

[William Pounds]

I'm planning on removing a load bearing wall, so I've been doing some preliminary investigation. Don't worry I'll have an engineer when I can find one willing to do a small job.

The wall in question is about 16' and is located on the main floor of a two story house. The basement has a 20' steel beam (W10x30) in the same location. I was concerned that placing the end post of the upstairs beam 4' from the end of the basement beam would stress the steel beam too much. So I plugged the numbers (1200 * 20 vs 1200 * 4 + 9600 + 9600) into a couple of beam programs and discovered that the deflection numbers actually decreased. I must be missing something here?

[Brian Whatcott]

Concentrating the loads near the ends of the basement beam reduces that beam's deflections.

Brian W

[rich]

Check the shear - it might be the limiting condition. Also even if the shear checks out, web stiffeners might be advisable.

[Rob Munach]

It is unlikley that shear or web stiffeners are required on a W10x30.

-rob

[Stormin Mormon]

I thought you'd say some thing like if you have one bottle of Jim Beam you get a lot of friends and some work done. Two bottles, you get more friends and less work.

[William Pounds]

Thanks for the responses.

Shear seems OK. According to the #s the beam is marginal in it's original configuration, although we've never experienced any significant bounce. My

1200 figure ((40L + 30L + 30D) *12) is probably 10% over code though.

[Rob Munach]

Most residential beams rarely see much over the structure dead load. I think I read that the average occupancy live load in a house is 6 psf. Additionally, the more stories a beam carries, typically, the less it bounces due to damping from walls etc.

-rob