Thread: Large opening in center of steel I-beam

Has anyone ever seen anything like this before? This is a steel I-beam, in the garage, that has had a large opening cut out of the center of the beam, to presumably make room for the garage door opener. It appears that additional support was welded along the bottom. Is this sufficient? Any advice? Thanks in advance.



Similar Threads:

• Knowledge Center
• Plumbing vent routed over beam in attic.
• Opening at bottom of guardrail
• Nails in foundation beam
• Steel framing

Originally Posted by Jason Boni

Has anyone ever seen anything like this before? This is a steel I-beam, in the garage, that has had a large opening cut out of the center of the beam, to presumably make room for the garage door opener. It appears that additional support was welded along the bottom. Is this sufficient? Any advice? Thanks in advance.

Jason,

Any deflection in the beam? Can't see any in your pic.

I see stuff like that periodically around here, but only in moment-frames (seismic bracing), not in supporting beams. I believe that specific portions of wood I-joists can be removed for duct runs and plumbing, so it might be acceptable. But, this is a steel beam and it is not something that I would be willing to bless in a report.

Since I am only a home inspector and not an engineer, would note the condition and recommend a structural engineer.

Well in case like this you may want to document the finding in your report with good supporting photos and if you are unable to vouch for the safetiness refer a structural engineer

That looks like a pretty big hole in the beam and it sounds like it is located at mid-span which would be the location of maximum deflection. I would certainly note it as a possible structural problem that should be checked as to whether there was a building permit on record for that hole or a structural engineer should investigate.

The beam is in pure bending at that location so the flanges are in tension (bottom flange) and compression (top flange). With no shear the web only serves to keep the flanges in their respective locations.

How was the plate added to the bottom flange? Was it welded across or along the flange? If it was welded across the flange the heat from welding may have weakened the flange.

Regardless, the beam has been modified (web cut out and plate attached to bottom flange) so I would recommend review by SE.

It may just be camera lens distortion, but if you hold a straight edge like a sheet of paper to the picture of the beam, it shows a serious sag in the middle of the bottom flange, but less along the top flange.
What would an engineer recommend? Probably a couple of long steel plates sandwiched over that hole.

Pic 2 is Victoria, BC's Blue Bridge, the last of it's type in this part of the world, slated for the scrap yard because it is too much work to keep it painted in the salty environment. They are afraid the concrete counterweights are going to come crashing down one day.

From what I remember from first year Structures years ago, it looks like buckling failure of the top flange under compressive stress where the web is missing may be a bigger risk for initiating failure than excessive tensile stress in the lower flange. However not knowing about the margin of safety and not being a structural engineer, I would agree totally with the recommendation to consult a structural engineer.

Originally Posted by John Kogel

What would an engineer recommend? Probably a couple of long steel plates sandwiched over that hole.

John, the bending strength of the wide flange beam is in the flanges, not the web.

Originally Posted by Bruce Breedlove

John, the bending strength of the wide flange beam is in the flanges, not the web.

Thanks Bruce. I'm no engineer, but if the web is not needed, why does the lack of one weaken the beam?
Or to put it another way, wouldn't replacing the missing portion keep the flanges from buckling or stretching?

I saw this exact modification. The home had two side by side garage door openings (each opening about 2.5 cars wide) with steel beams spanning over each opening. Overhead, the exterior wall sitting atop these openings consisted of a two floor (10 foot ceilings each), full depth brick veneer on wood framing. What happened was a deck was built over the driveway section adjacent to the building with the vehicle door openings relocated further out below the deck edge. That required the vehicle door openers be moved towards the newer door openings which required the steel wide-flange webs be notched out with a blow torch to provided a 4-5 inch wide, full height opening between the top the bottom flanges for passage of the opener carriage track. Upstairs, the floors sloped and wide drywall cracks where observed on the interior of the brick veneered wall. As the garage wide flange beams were trimmed out within a wood casing, it was difficult to see if the beams has deflected, but once I got a better viewing angle--yes; a combination of torch heat, excessive load and center location of the cuts had caused both beams to sag.

Originally Posted by John Kogel

. . . wouldn't replacing the missing portion keep the flanges from buckling or stretching?

Yes. The flange provides lateral support for the flanges so they stay in position and the loads remain (almost) pure tension and, more importantly, compression. If the hole is too large the beam flange under compression may deflect too much and fail.

Even though the beam hasn't exhibited signs of failure yet, it was put there for a reason. If it's seismic, the first tremor may cause the upper flange to buckle, resulting in potentially catastrophic economic hardship for the new owners.
If it's not seismic, time will tell whether it was actually necessary.
Either way, the beam needs to be evaluated. It was compromised far beyond industry guidelines. A hole in the center of the web is acceptable, but it's maximum size is determined by the height of the beam, the thickness of the web, and more.
Removal of an entire piece of it is unheard of. The top flange will buckle, and the bottom will bend, sooner or later.
Thanks for sharing the photo, it's earned a place in my collection of "Belly Laughs".

Originally Posted by bruce audretsch

Either way, the beam needs to be evaluated. It was compromised far beyond industry guidelines. A hole in the center of the web is acceptable, but it's maximum size is determined by the height of the beam, the thickness of the web, and more.
Removal of an entire piece of it is unheard of. The top flange will buckle, and the bottom will bend, sooner or later.

I agree. The beam and the effects of the hole and the plate (and associated welding on the bottom flange) should be evaluated by a SE.

From what I remember in my mechanical engineering classes, the web is what provides the strength here. Think of a 2x12 board. It bends much more easily in the flat position than it does in the on-edge position. I agree that this will result in compressive failure in the top flange. The extra plate welded on the bottom is not even close to sufficient.

I should point out that I'm not a home inspector but have engineering degrees in both mechanical and aerospace.

You've got to call this out and insist on engineering verification.

Bruce, you are assuming a certain distribution of load above, that may or may-not be the case. The photo depicts a 4' section and a garage door opener, it's easy to relate it some thing we have all seen before. But the SE referral was dead on.

THe web is critical to the "I" beam. The bottom and top flange are in tension and compression only with the web in place. Without the vertical web, the flanges will bend under substantially less load than the beam was originally designed for. This "I" beam has been severly comprimized. Somthing like cutting a 10" hole in a 2X12. Who ever cut the opening in this "I" beam did do a neat job-- nice clean lines.
My report would strongly suggest the beam be examined by a licensed engineer.

Originally Posted by Bruce Breedlove

I agree. The beam and the effects of the hole and the plate (and associated welding on the bottom flange) should be evaluated by a SE.

Everyone's comment on getting an evaluation by a SE is spot on.

Besides the seismic concern, the other is fire. Even a small fire with a hole that large is likely to cause a structural failure.

Jason

If this is in the middle of a simple span beam the bottom flange is in pure tension and the top flange is in pure compression. Assuming the beam was the correct size before the hole was cut the bottom flange would not need the additional plate because it is in pure tension. At the middle of this beam buckling of the compression flange (top) would be the issue. So removing the web reduces the stiffness of the top flange to resist compression loads which could buckle if the forces are large enough. You would have to do the math to get the right answer to your question. So adding the additional plate to the top would have been the better choice if it was needed.

Welcome to the forum and your first post.

Subject has been well covered, just wanted to acknowledge your first posting activity.

Originally Posted by Don Horn

This "I" beam has been severly comprimized. Somthing like cutting a 10" hole in a 2X12.

Don, the difference is that a 2x12 is not an I-beam. It doesn't have top and bottom flanges. Picture a wood I-joist. There are large knock-outs in the web to run ducts, leaving very little web. The top and bottom flanges do most of the work.

I agree that a SE should be consulted, and hopefully one already was when the hole was cut. For anyone interested, attached is some engineering information (ignore the math; just look at the pretty pictures )

Originally Posted by John Kogel

Pic 2 is Victoria, BC's Blue Bridge, the last of it's type in this part of the world, slated for the scrap yard because it is too much work to keep it painted in the salty environment. They are afraid the concrete counterweights are going to come crashing down one day.

There is a bridge just like that in Mystic Conn. It's a bit scary standing next to the bridge watching those big concrete weights moving

This has destroyed the integrity of the I beam. In your report I would stress that this is a safety issue and recommend a structural engineer look at this. Not only as a home inspector but as a general contractor I would never allow my employees or subs to cut out something like this. I can't believe it got by the building department.

Originally Posted by gene schafer

I can't believe it got by the building department.

I see this comment all the time here. Do any of you ever go to the building department and ask to see the permit file for the homes you are inspecting?
I have been the Building Official for a city with a population of 7,000 for over 13 years and only once has an inspector come in to look at the house file and he was a building official from another city doing an inspection for his sister who was looking at a house.

The hole in the beam concerns me as well, but a trip to the building department (before or after the inspection) would be a lot cheaper than having them pay for an engineer, especially if it was already engineered.

Very good point, If the beam was designed and approved, there is no issue.

I doubt the cut in this beam was approved by a structural engineer or was it permitted.
Usually a engineer stamped inspection letter is left with the owner on his recommendation on modifying a beam. Yes you could check with the building department, however it would be prudent to note in your report that it would be recommended to have structural engineer look at the beam if there is no letter. If this beam fails and your report doesn't put in this recommendation you might find yourself in court. Better safe than sorry

Originally Posted by David O'Keefe

There is a bridge just like that in Mystic Conn. It's a bit scary standing next to the bridge watching those big concrete weights moving

Thanks, David. I'll check that out.

The Johnson Street Bridge was designed under the direction of Mr. F. M. Preston, City Engineer in 1920. This is a bascule-type bridge in which one end rises while a counterweight lowers on the opposite end. The Johnson Street Bridge has two separate bascules, the railway section and the highway section. The Strauss Bascule Company Limited who held the patents on the design prepared the design for the bascule spans and the operating machinery. Joseph Strauss later went on to design the Golden Gate Bridge in San Francisco.

Bridge History | Johnson Street Bridge Victoria BC