Structural Engineer or Structural Firm Specializing in PEMB Modifications?

[muchtolearn]

We have a client that would like to make some extensive modifications to a PEMB. We have expressed concern over the problems this may create, but they intend to push ahead nonetheless.

Does anyone here know of a structural engineering firm that specializes in work with modification of existing PEMBs? I was able to find one using the widely known Google tool, but no luck otherwise. Any suggestions or recommendations would be appreciated.

Thanks!

 

[jayrod12]

Is the original company still in business. I have had good luck getting the owners to contact the original designers for any modifications (if the original designer still exists).

 

[muchtolearn]

The original company has declined to help out on the project. The client is adding on another PEMB and the original company did not win the contract for the addition.

 

[Archie264]

Well I can hardly blame them; companies don't usually help out the competition. The owner is trying to be too clever by half. He's going to end up with some Frankenstein abomination that he'll end up paying more for in the long run.

 

[Brad805]

Where are you located? I have worked a few times with one guy in Vancouver, BC. The biggest challenge normally is getting the data to figure out what reinforcement is needed. PEMB shop drawings are notorious for being intended for erection only. I agree your owner's decision could end up costing him more in repair costs, but maybe the changes are simple.

 

[BS2]

I have performed a few extensive modifications to PEMB's. A word of caution - double or triple your typical fee. These projects are time sucks.

 

[JLNJ]

Be careful. We were involved tangentially in a PEMB failure due to (among other things) the long-ago removal of girts their stabilizing effect on the column.

Convince the Owner to pony up and give the contract to the original PEMB company. It seems like it would be a win in the long run.

 

[muchtolearn]

My firm is located in NW Arkansas - the project is a bit east of us in north central Arkansas.

 

[TLHS]

I'm jumping on the bandwagon that says you should get this contract into the hands of the original company. You're asking for trouble if you can't.

I would also suggest getting your hands on "Metal Building Systems: Design and Specifications" by Alexander Newman.

 

[thaidavid40]

Does the winning PEMB company propose to certify the effects of their structure on the existing one? They should have an Arkansas-licensed PE who stamps their shop drawings. Those drawings should clearly show the interface between the two structures, and delineate any effects on such.
Dave

Thaidavid

 

[haynewp]

I would also check if another PEMB manufacturer would be willing to design the modifications (perhaps the mfr that won the addition). You will still have to obtain all the as-built information to provide to them.

 

[bisandcan]

Stay away from this project unless you are able to keep the two buildings completely independent of each other. Without extensive knowledge of how the original building was cared for, is all the X-bracing in place, you are taking a major risk bolting/welding on to the existing structure. As soon as you do, you now own that building and the new PEMB supplier will not assume any of that risk for you.

I am currently working on a project with an existing PEMB and a new PEMB. The new building is 10' away from the existing building, with an interior "breezeway" between the two. The new building has members that cantilever the 10' span to the new building, and the only thing we did to the old building is take the siding and girts off one side, and add siding and girts to where the new building was "attaching".

 

[JedClampett]

We're having the exact same experience at this instant. Except our change is pretty minor. We put in the constructor's contract that they were to hire someone (preferably the original PEMB manufacturer) to have them give means and methods to move a braced bay to another bay. In this case we have the original drawings (which by the way, have all kinds of warnings about changing the building without contacting the original designer), so they don't have the excuse of saying they lost the information. We sense that this is a major change that the original designer should be interested in and contribute to.
Well, when the CGC called the PEMB supplier, they refused to do it. Don't know why, but I don't think it was a money thing. We would have backed any change order they submitted. We were majorly pissed. We called some other smaller firms, to ask them and see if they knew anyone. No one called back.
I had my guy document that the original supplier (with names) refused to do it and we're doing it ourselves. We don't like messing with these for a lot of reasons, but the main one is that we can never get their members to work when we re-analyze them. Other reasons are proprietary member sizes and very hard to decipher drawings.
Once again, tell the owner it's going to cost 10 times what you normally estimate (you still might lose money) and remind them all the money they saved when they bought the building in the first place.

 

[muchtolearn]

Unfortunately, the GC has already awarded the contract and ordered the building from the new PEMB manufacturer. The two buildings will be structurally separated, but the GC has removed two frame lines from the end of the existing building in order to add on the new building. The new building has a higher roof line that will create some drifting snow on the existing building. Neither the new or old PEMB manufacturer will do the work for the modifications to the existing building.

 

[jayrod12]

I guess the only option is to get out there with some calipers and figure out the current sizes on site. I hope the owner is aware that there is ZERO chance of there being enough reserve capacity in the existing building to support any sort of snow buildup.

 

[Brad805]

Before going too far I would do some rudimentary calcs to determine the percentage increase in your forces. Assuming zero reserve capacity (highly probable if relatively new PEMB) figure out what the likely repairs may be. Then you can give the owner a shock price that might force him to re-consider his options. Money is a great motivator, and based on the shopping that has went on I suspect this owner will listen. I have done that many times before. We had one approach us about removing a single PEMB column. When I mentioned the cost to do so would be north of $200k, surprisingly they came up with a better location to move in their products. Here the breezeway idea sounds reasonable if space permits.

If after all of at the owner still wants to continue on this path, refer back to TLHS's comment about fees. Man lifts, calipers, limited access, liner panels,....it gets uggggly.

In defense of the PEMB suppliers, many of them cannot do this type of design very easily. Most big manufacturer's are so highly automated that they cannot feed this type of a design into their system for production. They make virtually nothing on the design side, so if they cannot make any money on the fabrication there is no profit for them. Why they include some of the warnings like they do one their drawings is puzzling, but I suppose they have lawyers.