Floor stiffening debate 2

[PropertyGuy67]

I'm a third party PE on a project. Building has floor stiffening beams in place. Owner is balking at the idea that the beams are "structural". It's obvious as heck to me that these are structural in nature, especially since the contractor said he jacked the floor slightly with the beams to get the floor plate level mid-span, but the owner is heading down the road of "prove it." Owner is saying if the beams were removed, the building wouldn't come down. Never in my life have I had to prove that a beam with a load on it is structural. My argument will be that there are clear and unambiguous load paths from the finished floor down through the base of the supports holding up the stiffening beams. Please fire away, shoot holes at will.

 

[BridgeSmith]

Just because "the building wouldn't come down" doesn't denote the absence of a structural failure. Excessive (unacceptable) deflection is also considered a structural failure. If the deflection of the floor would be unacceptable if the stiffening beams were removed, then that would be a structural failure, as in, the floor structure doesn't function in an acceptable manner.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[WARose]

Obviously you are dealing with someone who doesn't know what they are talking about. That's always tough. About all you can do is make your case and/or submit calculations to prove it.

One time I made the crack (when some PM kept saying he wanted to cut out a beam that was clearly needed)....."you take that out, and you won't need no elevator to get to the bottom floor". (Loosely paraphrasing a line from the original Alien movie. )

 

[r13]

My impression is that the beam wasn't on the project design drawings, but the constructor brought it in for erection purpose, and utilized it to level the floor plates in the mid-span. Is this the case (if not, ignore my comment)? Do you have access to the design drawings?

 

[msquared48]

The joists may have been in a deflected shape for years, having dried there under load over time. The beam may have been placed to provide support and control deflection.

Check the joists without the beam.

Mike McCann, PE, SE (WA, HI)

 

[Tomfh]

Check the joists without the beam.

Agree.

Whilst the beam may be structural in that it's carrying load, you need to show it is necessary to retain it.

 

[XR250]

I run into all the time doing inspections. Frequently, beams have been installed to remove bounce or mitigate sag.
My default position is that if the floor system meets (or met) code or the standards of construction during the era of the build, then it is not structural.

 

[msquared48]

If the beam is taking load, it is structural.

The real question the owner is raising is if the beam is necessary.

Just answer that question.

Mike McCann, PE, SE (WA, HI)

 

[r13]

The owner seems either have a very short memory, or confused. Didn't he been charged for the job of floor leveling with the beam cost added in? I think the contractor ought have explained the added cost, and the usage/need of the beam. Unless it was just a temporary set up for work. But I agree the comment above, "if the beam is taking load, it is structural".

 

[PropertyGuy67]

"I run into all the time doing inspections. Frequently, beams have been installed to remove bounce or mitigate sag.
My default position is that if the floor system meets (or met) code or the standards of construction during the era of the build, then it is not structural."

I see this all the time as well. Here's how I personally make the distinction between structural and non-structural. If the new component repairs, reinforces, or changes the performance of an existing load-bearing component, or creates a new load path, then that new component is a structural component. It has become a load-bearing component. On the other hand, if the new component is merely "fill" like blocking up an arched masonry opening, or replacing a facade system with another one, then that's non-structural.

Even in the most basic case of stiffening a floor for large format stone tile, you're changing the performance of the structure. You're going from L/240 to L/720. And not only is that non-prescriptive, you actually have to perform a basic calculation to make sure you meet L/720. I may be wrong, but to me anything like that is structural.

 

[PropertyGuy67]

"My impression is that the beam wasn't on the project design drawings, but the constructor brought it in for erection purpose, and utilized it to level the floor plates in the mid-span. Is this the case (if not, ignore my comment)? Do you have access to the design drawings?"

The beam arrangement does not show up in the structural plans from the 1960's, and the owner freely admits to adding it several years ago.

 

[PropertyGuy67]

"The joists may have been in a deflected shape for years, having dried there under load over time. The beam may have been placed to provide support and control deflection.

Check the joists without the beam.

Mike McCann, PE, SE (WA, HI)"

Unfortunately I can't remove the beams. It was obvious from the site visit that about half of the joists were jacked up. If I allow those to sag again, his travertine tile will crack.

 

[BridgeSmith]

If the beams cannot be removed, why does it matter how they are defined?

Or are you saying the owner wants to remove them anyway? If so, just tell him what what you just told us - "It was obvious from the site visit that about half of the joists were jacked up. If I you allow those to sag again, his the travertine tile will crack." If he still wants to do it, put that assessment in writing and get confirmation that he received it.




Rod Smith, P.E., The artist formerly known as HotRod10

 

[r13]

The beam arrangement does not show up in the structural plans from the 1960's, and the owner freely admits to adding it several years ago.

Ha ha, if my eyes have no problem, the owner, himself added the beam then, and wants to remove it now. Yes, get writing from him, if he insists, and willing to override his reasoning in adding this beam and leaving it is place for years.

 

[r13]

Is this a pre-sale inspection?

 

[PropertyGuy67]

"Is this a pre-sale inspection?"

This is a commercial property transaction, where the property condition assessor found these beams and posts and no permit paperwork or engineers report in the FOIA request. The buyer hired me to assess it, and the owner is balking at the idea of doing it over properly. The arrangement lacks fasteners and lateral restraint, not to mention that the posts rest on slabs of unknown thickness and reinforcement. Several of the joists are also turning at the point of support, so it needs blocking, imho.

 

[PropertyGuy67]

What is the trick in quoting a prior post? I don't see a button for that.

Edit: found it.

 

[r13]

It should be considered a building code violation - alteration without permit. Just relate to the buyer the problems, and let him to decide. I think the current owner is a street-smart, DIY type of person, not willing to admit his wrongful action until his head hitting the wall. For the buyer, it may be no harm to allow the beam stay in place, if the problems can be resolved within reasonable amount of effort and cost. Otherwise, negotiate a lower purchase price, then re-do it himself. Or, the last, cancel the purchase.

 

[Retrograde]

If you are working for the potential buyer why do you need to prove/justify anything to the current owner?

 

[msquared48]

Travertine??? L/600 minimum on the joist deflection!

Mike McCann, PE, SE (WA, HI)