Since the contractor’s responsibility is for materials and methods, how much information drawing details should provide?
Let’s say that the project calls for a 2HR fire rating of an existing steel beam. The architect specifies the UL number, the gypsum board type, but when it comes to the actual installation elements should they be called out in the detail?
Does providing more information about the installation process shift the contractor’s liability over the architect?
Hi Oana,
Yes, you’re exactly right! Providing information on means and methods can give the contractor the ability to say, “well, the architect told me to do it” if something goes wrong. As the architect, you always want to limit liability. Therefore, you typically don’t describe installation, although you might describe the parameters around installation.
For example, if you adding a two hour fire rating to an existing steel beam you might note in your detail, “protect adjacent areas during construction” and “drawings are based on existing drawings and site observation, architect has done due diligence to represent existing site conditions. If conditions differ notify architect immediately. No structural elements to be removed or damaged.”
These broad notes give the contractor parameters for work. An example of something you wouldn’t want to note for example is “start framing on west side of beam and continue around beam to provide consistent gyp finish” or “utilize scaffolding when constructing gypsum beam enclosure” It is their job to determine the best method for construction.
A detail would show more information about the construction of the enclosure, but not how they should build it. It would show overall dimensions of the enclosure, but not the dimension they need to cut the framing to provide the finish face dimension.
One final note is that this is when specifications become very important. You don’t typically tell the contractor what kind of gypsum to use because they need to have some flexibility in order to get competitive pricing. So, in your specifications you will list out acceptable gyp manufacturers and product requirements. You will also have a section on fire sealant that will outline the requirements it must meet. So, while the contractor is responsible for materials, it is the architect’s duty to provide the parameters these materials must meet.
Hopefully this helps!
Darion,
Your clarification is very useful!
I have 2 additional materials that I’d like to discuss on the same topic.
In this case, isn’t there a surplus of information? In my opinion, for example, calling out the channel brackets, the corner angles would mean detailing the installation process.
Since his work is not a classic way of using the materials, he might need to specify a lot on the methods. In this particular building, I also think that he might have also coordinated in detail the site processes to preserve the existing historical conditions.
Do you think that in such a situation, in order to avoid liability transfer, the design-build delivery method is the only available option?
Thanks
Hi Oana,
Calling out the products isn’t necessarily detailing how to install them. Telling the contractor how to install the angle brackets (for example what tools or techniques to fasten them) would be detailing the installation process. This being said, it’s a fine line and the architect needs to use their best judgement. Architects either provide too much or little information all the time.
Below is a screenshot of my firm’s general notes. In our drawings we stipulate the contractor’s responsibility is to reference UL directly for ratings:
Zumpthor’s buildings and unique use of material I would describe as outliers, and not the norm. Typically your goal as an architect is always to limit liability. In the example above, I think your assessment that the design build delivery method would work best is spot on. However, I’m sure other contract types might have been possible, especially if the firm itself was willing to construct mock-ups. It’s possible that Zumpthor, as a well established architect, might be willing to accept additional risk in order to pursue his designs. Perhaps the firm carries additional insurance.
There’s a number of situations – architects may accept additional risk in some situations if they believe it will be ‘worth it’.
This is a good discussion because there are some grey areas here – does anyone else have other opinions or anything to add?
