I found this steel beam today. It was located in the middle front of the house, a cape cod. There were two of these I’s welded together.Has anyone seen this before. I hope the photo shows the ripples at this size.
I can’t say I have ever run into a double wall hollow I-beam before. To me the ripples you are talking about look like they are at regular intervals. To me that would indicate a welded plate between the two sides of the I-beam for reinforcement (kink of like fire blocks in 2x4 wall construction).
I thought they might be welds or marks due to overheating, but the longer beam at the rear of the house has no such imperfections. I could not get my head up to view inside. The shot of the end is the rear beam with no ripples.
So is it coincidental that the deflections are immediately below the joists? What was upstairs?
It is a bad angle but to see the ripples, I had to shoot it from the side. They are not directly below the joists, there is a slight 1 to 2" offset.
Loads from the joists will not cause that.
The beam was probably purchased for cheap due to the imperfections since it is ok for residential construction but may have been rejected for a commercial project.
Good response. Sounds very logical to me.
It looks like welding to me. I don’t see any signs of failure that I would expect if the ripple was due to loading.
Loading on this box beam is definitely not the issue here.
I agree with Curtis C. that welding created this oil canning affect on the web portion of the beam.
The rectangular tube steel, however acquired, was adapted with a top and bottom flange, if you look closely, and welded in the field or in a shop.
Most likely if in the field, they used an X7018 electrode which produces a lot of heat an can contort the web as you see it when not properly controlled. The shop would have used a X7024 electrode or Mig Welder of the same equivalent, and produces even more heat.
Did not catch it the first round, but noticed it this time.