It's the same old story. I'm refinishing the basement and there is a lally column in the way. It supports a W8x18 beam with a span of about 11' 3''. I need to move it about 4' to make the total span 15' 3'' +/-.

I talked it over with my father who has been designing structual steel (but is not an engineer, his stuff has to get approval and usually does the first time) for over 20 years and he said it would be no problem. But since we're talking about the structure of my house, I figured that I'd get as much input as possible.

Now the house is a ranch, 1998 construction with a truss roof. The area above the 15' span is a living room/kitchen with a common cathedral ceiling and a partition wall that only runs about 3/4 of the way up to the ceiling. The only things of substantial weight over the beam are kitchen cabinets and a stove.

So I'm thinking that the only thing this beam is supporting is the floor in this particular segment. (After this segment is the bedrooms and such, but there are plenty of columns there.

So my plan of action is this- Get 2 2x8x16 boards and set them in the W8 on either side to beef it up and try to minimize sag and bouce. Drill 1/2 inch holes every 2 feet through the web and bolt the 2 boards and the W8 together. Then put my new column in and remove the old one.

My fathere has moved several columns in the past including one in his 2 story 1930s construction house with a baby grand piano over it, so I have a lot of faith in his assessment.

Mike

 

I didn't run any numbers but I don't think the wood you are thinking about adding would gain you any strength to the beam - welding steel plates in the web of the beam would but I don't think the 2x's would be worth the holes you'd have to drill. I doubt you'd ever get them tight enough to the I-beam to get them to act as one.

For a few hundred bucks and a whole lot of piece of mind, have a structural engineer put his stamp on it.

 

The problem is probably less the beam and more what the column's going to sit on.

I'd expect there's a footing under the existing column, hidden under the concrete basement floor. Move the column 4-feet, and it's just standing on the floor.

Or did you just leave out the part about opening up the floor andpouring a new footing?

 

I left that out. A new footer is a must.

Mike

 

I second Ray's post about getting a structural engineer on board.

Jason

 

as long as youre putting a footing in , you should be ok...
doesnt your clerks office or code enforcement have guidelines to go by?

 

He's talking about moving a lally column, which supports a beam, so "you should be ok" doesn't cut it. The reason engineers usually do this type of thing is that the "guidelines" are incredibly complex. There could be a load path or load-bearing wall above that lally column. Move it and whoops...cracking drywall or plaster everywhere when the beam flexes under the sudden additional load.

Jason

 

There are no load bearing walls over this part of the beam.

My father spoke with an engineer he works with over the phone and he said that it will be ok.

It's also going to be a slow move. There is no sense in rushing this. But even after all this, I might not move it. It's looking to be more of a PITA than it's worth. In any case, I'll be putting up a joist mounted "drop ceiling" so moving it after the fact should be no problem.

Mike

 

Don't drill holes in the beam. The holes cause stress risers, which can lead to cracks and failure over time. This is why you see beam clamps in factories and warehouses, and not just a bolt through a flange or web. The only holes allowed in supporting beams are engineered in and usually at structural attachment points.

 

Forgot to mention that 2x8s are out. The engineer said that although they might do something for resisting bounce and sag, that the effects would be minimal.

He also said that the light loading over this span meant that it would really matter anyway.

At least that's what I can type out half cocked.

Mike

 

Properly sized and cleanly drilled holes in the neutral axis of a steel beam aren't a problem but in this case would be useless for adding strength to the beam. The EI (modulus x moment) of the double 2x8 would be around 300, roughly 1/6th of the EI of the W8x18's 1850±. Assuming you could get bolts tight enough to make it all act as one beam (you probably couldn't), the wood wouldn't amount to a hill of beans.

Probably why you don't see built up beams with wood and steel.