7 meter (23 feet) beam - simply supported - split in half and then welded on site - Any Concerns?

[dacdacdac]

Hello, I'm looking at a construct-ability problem.

We need a structural beam that spans 23 feet at a residential home, its fairly heavy beam for a home, w10x10 or W250x73. The problem is that we want to work indoors, and to do that we would have to cut the beam in half, jack it and do a full moment weld connection midspan.

I'm curious if there are any alternatives or concerns with this approach?

Thanks in advance!

 

[JAE]

If the two halves are in place - the top flange welding would most likely be very near wood floor framing above - fire risk.

You would want to have a qualified welder for the required full-pen welds.

Some kind of bolted flange plate connection could be used if there was enough clearance top and bottom - you would need to pretension the bolts so again - clearance to get a wrench up at the top flange might be an issue.



Why not use a beam stretcher?

 

[AELLC]

This sounds like yet another non-engineer trying to get easy free advice on the Internet.

 

[rb1957]

i'd cut the beam in 3rds

Quando Omni Flunkus Moritati

 

[oldestguy]

What's wrong with setting the joint on a post?. That joint then needs only a simple connection, such as a web plate bolted to each beam, enough to keep them together while joists are set, etc.. Most of these beams get set on posts whether posts are needed or not. Tell 'em there is no other way. Besides inside that smoke is hazardous. It stains everything.

I question how the house got built without the beam to begin with.

 

[AELLC]

This is usually a home owner or builder question when they are trying to accomplish a re-model or addition.

 

[dacdacdac]

I'm an engineer. 5 Years of structural work on large construction, but now I'm doing construction management and haven't touched structural design in a while. That being said it is a home construction, I am adding a 100 sqft back addition to a house.

Jae: Thanks for your response. You mean fire risk during the welding process, correct? Otherwise as long as there is enough clearance a full moment connection with two welded plates top and bottom should be sufficient right?
What is a beam stretcher?

rb1957: Thats a good point, but i feel that it would add signifincat work, i'm trying to keep things cost efficient, I have thought about doing 2/3 and 1/3. That might work.

oldestguy: Maybe I didn't explain it well. its a house renovation, we are removing a wall and adding an addition. This beam is going to pick up new loads and loads from the removal of a perimeter wall (plus some roof loads).

So sounds like you all agree its is normal for a small job to have split beams? We basically want to avoid having to bring in a crane and also this allows the contractor to work from the inside in the winter (its really cold in Toronto right now)

Thank you, all.

 

[AELLC]

OK, just checking up on you.

I was suspicious because it was your first post and there is no such thing as W10x10, and if it was, that would be a very light beam.

Are you sure you need a steel beam? Have you considered parallam or glulam?

 

[EngineeringEric]

Was lateral Checked? jsut something that i see overlooked on nearly every "remove this wall with a wide open, 23' wide, space. Code is 20' between face of panels on CS-WSP.

That space means the wall is no longer a prescriptive BRACED WALL LINE; no longer in the residential code and you are now enter shear walls and collectors. This is an issue that I hope was addressed....?

I agree with others that bolts would be better than full-pen welds, if possible.. but welds are do-able

 

[dacdacdac]

I'm Canadian, I dont' have my codes with me. I just googled it properly, the beam is a W10 x 49. I might look at wood options again, I did some checks with Weyerhaeuser and they all needed a lot of depth I can't afford (I dont' want a bulkhead). I guess I didn't consider a glulam, but that might still have the issue of weight/size being combersom for interior work. Is a moment detail for wood beams better or worse than a weld detail for split steel beams?

No worries.

 

[rb1957]

first one to make a Rob Ford joke has to buy a round in the pub!

i dislike a butt weld at the point of maximum stress. i'd nest angles and a web splice and a bucket of bolts ... but you guys don't like bolts. maybe a lap splice, instead of a butt weld ? maybe weld angles (into the corners of the I-beam) ?

Quando Omni Flunkus Moritati

 

[dacdacdac]

EngineerEric: Thanks for bringing it up, I have definately given the overall lateral bracing of the house some thought. This small wall was not providing much shear support.

 

[JAE]

Don't use butt welds - use full pen bevel groove welds performed by a qualified welder.
Probably want to test the welds too.

Yes - fire from welding operations - be very careful as sparks get shot out and embedded in wood sometimes and smolder for hours before going off.

Beam stretcher: deflection = PL/AE. Just need a unit to pull with a very big "P" to get the delta you need to stretch across the room!

 

[dacdacdac]

I dislike Rob Ford butt welds as well. I like the angles suggestion in the inside corners, but I'm afried the beam might be too small to allow for proper walling in the small space... I'll have to draw up and think about it.

 

[EngineeringEric]

Just checking! glad it was looked into.

LVL/Glulam for spans like this will weight the same as a steel beam, but they can be installed in multiple plies to reduce the lifting weight. the plies jsut get bolted together, but steel has more capacity than these for equal depth. (typically)

 

[AELLC]

The LVL/GL options are very much cheaper and easy to work on than steel. Splicing in wood is impossible, you need an interior post. Splicing in steel will be unfeasible economically and practically IMO. You really want to get this in one piece, be it a single lam or 2 or 3.

The Weyerhaeuser software may be over conservative in checking deflection criteria, so wood may work after all. We need more info.

A W10x49 is a common column size, so you are saying you have less than 12" to work with, and would have to resort to a very inefficient beam size.

 

[dhengr]

Dacdacdac :
Why don’t you show us a cross-section through the existing wall, roof and foundation, reasonably to scale, with dimensions and loads, and complete details up at this new beam location, the info needed for a good design discussion. Maybe an elevation of the existing wall too. Then show a second section with the addition, again dimensions and loads etc. Since you haven’t done any of this construction or design, someone who has might see some options which you haven’t thought of. By the time you screw around with two sections of beam and a do proper job on the connections (welded, bolted, inspected, shored during work, etc.) your contractor can rent a crane truck or lift for a day. With that big a beam you better check your foundation conditions at its two bearing points.

 

[JStephen]

If you splice at the third points, the splices are potentially easier due to reduced moment, and might allow easier bolting.
Possibly two channels back to back for reduced weight?

 

[Triangled]

i liked the OP W250x73 ... tall enough to do the double duty as a shear wall as EngineeringEric adroitly observed. in lieu of that, I'd definitely go with the beam stretcher.... or those new antigrav beams.

for a 23' span for a 100 sf exterior back addition, i'm envisioning a 23' of exterior wall/glass/window removed and a 4'+ room added... maybe i'm wrong, but i'd consider if alternative construction procedures as Dhengr alluded to above, might facilitate the installation of a single piece beam.

 

[tony1851]

I don't see the sense in trying to weld in a house.
A problem I'm dealing with is similar to yours, a 9m long simply-supported beam in a domestic roof.
It's a 356 x 171 x 67kg, and we're splitting it into 3 (as JStephen) and doing straight-forward splices with pre-loaded bolts.
With the cutting/drilling of the plates it may not be as cheap as welding, but probably cheaper than replacing a burnt-out house.