| Author |
Message |
Edward J Dueppen, RA, CSI, CCS, LEED AP
Senior Member
Username: edueppen
Post Number: 19
Registered: 08-2013
| | Posted on Friday, December 18, 2015 - 09:28 am: |    |
We have an issue on a large hospital project about having items prefebricated off-site that we assumed would be site-built. Specifically the construction manager has determined it would make more sense for them to prefabricate the patient bathrooms off-site and crane them into place later rather than built them in-situ.
At this point in the discussion they have indicated they will be including the following in the prefabricated bathroom units:
- floor slab
- metal wall framing
- door frames
- cement board and gypsum sheathing.
- waterproofing
- tiling
The more I think about this, the more alarmed I become. When I specified all of the components, I envisioned them as being installed on-site. But I never envisioned these components being fabricated off-site, lifted onto a truck, shipped many miles, and then lifted into each floor of the building. I'm not sure about how these components will withstand the vibration, stresses, and potential racking due to these moves. Consider the anchoring of the sheathing to the metal framing, the integrity of the waterproofing membrane from floor to walls, the adhesion of the ceramic tile to the substrates, etc.
Do I have a legitimate concern, or is this merely contractor means & methods?
Should we be issuing some sort of written disclaimer that we intended all of this to be site-built?
Should I be adding something to our front end for future projects?
I would really appreciate the wisdom of this forum.
Thanks in advance,
Ed |
Jeffrey Wilson CSI CCS SCIP
Senior Member
Username: wilsonconsulting
Post Number: 186
Registered: 03-2006
| | Posted on Friday, December 18, 2015 - 11:12 am: | |
Your concerns are certainly legitimate, and the issues you raise definitely warrant consideration. I have a client that has made prefab construction part of the design, and I developed fairly detailed specs that addresses many of the potential problems you mention -- including a section specifically for bathroom modules.
Of course, it's a different matter if the CDs have not considered the possibility of off-site construction. You're right -- it would be wise to include in the documents some language that allows for scrutiny of methods used for prefabrication if they are proposed by the contractor.
The best approach in your situation might be to raise all the questions you have for discussion w/ the builder to make sure they're taken into consideration in the fabrication & delivery of the modules.
Jeffrey Wilson CCS CSI SCIP
Wilson Consulting Inc
Ardmore PA |
Jeffrey Wilson CSI CCS SCIP
Senior Member
Username: wilsonconsulting
Post Number: 187
Registered: 03-2006
| | Posted on Friday, December 18, 2015 - 11:14 am: | |
I am willing to share my office master for prefab bathroom modules: jeff at WilsonConsultingInc dot com.
Jeffrey Wilson CCS CSI SCIP
Wilson Consulting Inc
Ardmore PA |
David E Lorenzini
Senior Member
Username: deloren
Post Number: 173
Registered: 04-2000
| | Posted on Friday, December 18, 2015 - 11:19 am: | |
One thing you might try is to request a full scale mockup of the entire module for approval before prefabrication begins.
David Lorenzini, FCSI, CCS
Architectural Resources Co. |
Colin Gilboy
Senior Member
Username: colin
Post Number: 418
Registered: 09-2005
| | Posted on Friday, December 18, 2015 - 11:22 am: | |
There is a section in 4specs for prefab modular bathrooms:
http://www.4specs.com/s/22/22-4900.html
Colin Gilboy
Publisher, 4specs.com
435.200.5775 - Utah
800.369.8008 |
Michael Chusid, RA FCSI CCS
Senior Member
Username: michael_chusid
Post Number: 104
Registered: 10-2003
| | Posted on Friday, December 18, 2015 - 12:52 pm: | |
In line with David's suggestion of a mock-up, is it enough to view the mock-up in the fabricator's plant? Have it transported a distance equal to the trip to the site and hoisted several times as it might be as it is staged and then placed on site. That way you can inspect for damage.
Michael Chusid, RA FCSI CCS
www.chusid.com www.buildingproduct.guru |
Edward J Dueppen, RA, CSI, CCS, LEED AP
Senior Member
Username: edueppen
Post Number: 20
Registered: 08-2013
| | Posted on Friday, December 18, 2015 - 02:02 pm: | |
Jeffrey - thanks for the confirmation of my concern and I will contact you for the document. Do you include any front end language regarding this? Possibly something to the affect "Products in project are intended to be fabricated and installed on-site unless prefabrication is indicated. If Contractor elects to prefabricate work not indicated to be prefabricated, Contractor accepts responsibility for prefabrication including, but not limited to, verification of product suitability for prefabrication, and design and stresses related to shipping, handling, and lifting of prefabricated items."?
Michael - I really like your idea about the mockup and have shared that with the project team. Thanks! |
Colin Gilboy
Senior Member
Username: colin
Post Number: 419
Registered: 09-2005
| | Posted on Friday, December 18, 2015 - 02:08 pm: | |
In double checking the 2 listings, I deleted one leaving just Oldcastle.
Colin Gilboy
Publisher, 4specs.com
435.200.5775 - Utah
800.369.8008 |
Guest (Unregistered Guest)
Unregistered guest
| | Posted on Friday, December 18, 2015 - 06:45 pm: | |
The concept of including front end language with regard to where products are intended to be installed is an interesting one. Personally, I don't think it is necessary.
I don't really care if my project's metal stairs are painted in the field or in a shop as long as when the stairs are done the final coating achieves the specified work result (obviously, some work results would require shop application versus field application). The same could be said for your bathrooms, right? As long as the end result is what you specified, does it matter where the contractor builds them?
Assuming the general conditions is A201 or something similar ... the contractor shall be solely responsible and have control of construction means and methods. You've specified the work result ... how that result is achieved is up to the contractor to figure out. If they decide to prefabricate off site and it is damaged during shipping, it's still their responsibility to correct the work and achieve the work result that the contract documents require.
That said, the nature of constructing them off site, transporting them, and installing them in the final project would probably require a different design with different materials and products.
I can't quite tell from your posts if the project is still under design or if it is under construction at this point. If it is still being designed, I'd recommend getting the owner to approve the idea of prefabricating and to pay for the subsequent (re)design of the project to achieve that.
If you are under construction, I'd recommend you make sure to get a change proposal from the contractor outlining the benefit to the owner and agreeing to accept responsibility for the redesign of the portions of the project affected. The owner can then decide whether or not to accept the proposal.
Either way, I'm assuming there would be a definite benefit to the owner in the form of a savings of time, money, or both. If not, shoot the proposal down now as it will just mean more work for you with no benefit for your client. |
Steven Bruneel, AIA, CSI-CDT, LEED-AP, EDAC
Senior Member
Username: redseca2
Post Number: 525
Registered: 12-2006
| | Posted on Friday, December 18, 2015 - 08:10 pm: | |
When prefabricated building modules (as in entire rooms) fail, it is usually in the joint between two modules or between a module and the conventionally constructed building. This is doubly true if this joint is part of the exterior building envelope. I would want all those joints and a truncated sample of the construction on the other side of the joint on all sides, top and bottom, of the pre-fab unit to be included in the mockup. |
Edward J Dueppen, RA, CSI, CCS, LEED AP
Senior Member
Username: edueppen
Post Number: 21
Registered: 08-2013
| | Posted on Monday, December 21, 2015 - 09:17 am: | |
Guest - I appreciate your comments and I agree that the contractor is contractually responsible for means and methods. There is a fine-line here. The project is currently under construction. I agree that off-site production does suggest some design and product changes. But you also present a conundrum. If front end language to restrict prefabrication is not necessary and not included, then how do we require the contractor to provide a change proposal for prefabricating the bathrooms?
Steven - good idea about what to include in the mockup! |
Ronald L. Geren, FCSI, AIA, CCS, CCCA, SCIP
Senior Member
Username: specman
Post Number: 1374
Registered: 03-2003
| | Posted on Monday, December 21, 2015 - 11:32 am: | |
Why would there need to be a change proposal for prefabrication if the contract documents are silent on the method? This is contractor's means and methods, which are nonnegotiable once a construction agreement is executed.
If the contractor can achieve the results through a less-expensive process, then he can pass that savings through the bidding/negotiating process in order to secure the contract; thus, the savings is already incorporated. If the process is considered after the execution of the contract agreement, then the contractor has widened its profit margin--it does not need to pass the savings on to the owner.
However, if the contract documents do stipulate either a prefabricated or in situ method, then a change proposal would be in order if the contractor was proposing the method not specified, just like a product substitution.
Let's turn the tables on the issue. What if the design team submits a proposal with the idea that they will prepare the documents using standard CAD and they get the project. Later, after the contract is executed but before design begins, the principal hires a new employee that is a wizard with BIM, which allows the office to prepare the documents in less time. Would you pass the savings on to the owner?
Ron Geren, FCSI, AIA, CCS, CCCA, SCIP
www.specsandcodes.com |
Guest (Unregistered Guest)
Unregistered guest
| | Posted on Monday, December 21, 2015 - 12:04 pm: | |
Maybe you don't need a change proposal, but if that is the case you really have nothing to worry about because your design is adequate.
However, not changing anything from the original design is most likely going to be very difficult for the contractor to achieve. Every time something like this has happened to me, the contractor needs to change something; material, product, installation method, etc. Make sure all the manufacturer's installation procedures and warranties support prefabrication. If they don't, and the contractor needs to find a different material that will allow it, that's a change proposal. Don't let them squeeze it through in a submittal or RFI.
On the other hand, if they aren't changing materials and products, they usually aren't addressing everything they need to in the submittals. Look at the TCNA methods you've hopefully specified for installing tile. There are limits to substrate deflection. Your partition framing probably takes into account normal loads that the partitions would encounter in the building, but what about loads encountered during lifting, trucking, etc.? If the contractor isn't addressing these, you need to point that out in reviewing the submittals. This will most likely result in a change once they start to address these things. That's a change proposal.
It's probably even worse for a tiled floor. How do you get a tiled floor from a truck to the building without changing something from the original design? You mention in your OP that they are intending to fabricate the floor slab off-site. Are they documenting how the slab will be capable of handling all the stresses of being lifted and placed keeping in mind substrate flatness and deflection? How will that then be placed in the building? Will they be changing anything about the designed floor slab (additional slab recess, thickness, additional structure)?
I've focused a lot of the tile, but what about the ceiling? You didn't mention anything about it in the OP. Assuming you specified the partitions as non-structural metal framing, how they propose to keep the ceiling in place during transport and lifting. Will the non-structural framing now need to be structural, requiring a different design than was specified? Even without a ceiling, will the walls be necessary for structural support when lifting and placing the modules?
Chances are there will be a change in there somewhere. You just need to administer the contract well enough to find it, and to make sure that everyone follows the documents when it comes to modifying them. |
Guest (Unregistered Guest)
Unregistered guest
| | Posted on Monday, December 21, 2015 - 02:13 pm: | |
Ron, that would depend on how the contract was written. If it stipulated the software, I would either be bound by the terms to stick to CAD or modify the contract to include BIM. If it is completely mute on the issue of software, I would be ok to use whatever software I have at my disposal.
That said, I think your example is confusing the issue rather than clarifying it. We aren't talking about the contractor simply using a different hammer or saw. They are changing the design to suit the construction method rather than the other way around. The documents are (for the most part) already written around in-situ construction. They may not explicitly state it, but it is contained within them through requirements to comply with manufacturer's installation methods, industry methods and standards, etc.
If there isn't any of that embedded in the documents, then there is nothing to worry about if the contractor needs to change the place of construction because there is no conflict. The documents would theoretically work for both potential construction locations; on site or off site.
However, if it is embedded in the documents, there is no need to state it again. In fact, if you do (at this point in the project) it not only opens the door for potential conflicts within the documents, but also gives reason for the contractor to ask for more money. Adding in the extra language in Div 01, extra requirements for mockups, etc., is all they would need. The architects' efforts to protect their client just cost the client more money, the contractor has increased their profits, and the architect has probably lost profits because their extra effort happens without compensation.
Compare that to finding the embedded requirements in the documents and holding the contractor to them. Now the contractor is forced to accept any changes for what they are, and the owner can either approve or reject them and receive any savings, or pay any extras (maybe they are ok paying more if it means a shorter schedule). Either way, the owner is well aware of what they are getting and there is the opportunity to add in any extra services and requirements for mockups (and more). Everyone is aware of the full cost/savings and necessary requirements of the changes. Then the architect and contractor are both compensated fairly for their work. |
Ronald L. Geren, FCSI, AIA, CCS, CCCA, SCIP
Senior Member
Username: specman
Post Number: 1375
Registered: 03-2003
| | Posted on Monday, December 21, 2015 - 04:26 pm: | |
Guest Quote: "On the other hand, if they aren't changing materials and products, they usually aren't addressing everything they need to in the submittals. Look at the TCNA methods you've hopefully specified for installing tile. There are limits to substrate deflection. Your partition framing probably takes into account normal loads that the partitions would encounter in the building, but what about loads encountered during lifting, trucking, etc.? If the contractor isn't addressing these, you need to point that out in reviewing the submittals. This will most likely result in a change once they start to address these things. That's a change proposal."
The contract documents stipulate minimum requirements. If the contractor chooses a different mean or method of complying that requires more restrictive requirements, that's the contractor's problem. Using the tile example, if a maximum deflection is specified for an in situ installation, then when a prefabricated installation is installed, it must comply with that requirement. However, if a contractor does not take into consideration the other loads associated with prefabrication and the unit fails during transportation or placement, the contractor will have no grounds for a claim--it is not the owner's or A/E's fault, even if they did review the prefab submittals. Even if the contractor considers these other loads, the additional loads are based on the contractor's choice of a specific mean or method. The contractor should not and, in all likelihood, cannot make a claim for additional costs--that's an concern a contractor must take into consideration when selecting means and methods for a project.
On the other hand, if the drawings explicitly show and installation that can only be provided via in situ construction, then using a prefabricated method would be a change from the contract documents.
I don't think the BIM vs. CAD example is confusing at all. CAD is like the in situ method by preparing the drawings line-by-line, whereas BIM is the prefabricated method that incorporates building components using BIM objects.
If the RFP required BIM, then you would have incorporated that into your fee, either negatively or positively, depending on your firm's expertise with the technology. That is similar with contractors--they may have plenty of experience or no experience using prefabricated construction, so the costs will negatively or positively affect their bids as applicable.
If a contract is silent regarding method, then the option is up to contractor (prefab or not) or the designer (BIM or CAD), depending on which one provides meets the requirements at the lowest cost.
Ron Geren, FCSI, AIA, CCS, CCCA, SCIP
www.specsandcodes.com |
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