We have been asked by a government agency to produce a report on the durability of materials and assemblies selected and specified for a project in Northern California.
Other than the fact that being publicly-funded, the materials/assemblies specified are open to substitution by the bidders/contractor, how does one approach this subject and what comparative standard do I use to demonstrate that a material that I know is durable, such as stainless steel, is more durable over the life of the building, expected to be 100 years, than weathering steel (Corten or Mayari)?
Are there studies that demonstrate the durability of concrete, glass, aluminum, etc. in an urban environment for instance?
As I keep thinking about this request, it seems that it needs to be better defined and may be difficult, if not impossible to answer in its present form.
Any help would be appreciated.
After you “retain” experts, scientists, etc. in each of the respective fields for each and every material and assembly to be reported upon, and after these experts, and scientists conduct their very scientific, long-term (i.e., multi-year) studies…This maybe an opportunity for long-term AND “reimbursed-by-your-client” study…JK
WTH…are you a materials researcher…or architect/designer?
Why is this agency concerned? What durability issues are they concerned about? How much are they willing to pay for this effort?
What level of performance are they expecting? This may influence the amount of effort.
Is this for one of the projects your firm designed? Is their a dispute with the designers of record?
This is an open ended question that has no absolute answers. The answers are dependent on the specific locality and design.
You may want to try using Whitestone Research life cycle and maintenance data that is used to predict required building maintenance.
www.whitestoneresearch.com
Thank you all for your insights. I agree that the answer or answers to the request is dependent on so many factors that the question needs to be re-framed. I suspect that our clients client is looking for life cycle cost, which would be more logical than durability.
The design team (our client) is on the hook contractually to provide a report on the durability of materials selected for a large transportation hub in California. I suspect that no one thought about this question when the contract was signed it must have been buried in the small print. We tried and are still trying not to get involved, but by default no one else on the team wants it, so it fell in our lap.
Any further thoughts on the subject would be appreciated.
This strikes me as a multi-dimensional issue having to do not only with material properties but also the conditions of use and exposure as well as maintenance. More durable materials may mean less maintenance, but the maintenance may become more critical to the long-term durability of a product.
In the wrong exposure, stainless steel (especially Type 304) may be less durable than A36 steel with a rigorous program of maintenance (think Golden Gate Bridge).
I think you are on the right track thinking about life cycle cost. Some of the really durable materials take 30 to 50 years to achieve a payback. I also suspect that many of those analyses don’t really have a “present value” component which pushes the pay back way out there.
You may find it easier to provide a report where you discuss the relative choice of materials and systems based on durability issues. I would expect that a life cycle cost study would require more work and not be as useful in informing the design.
This may be one of those situations where you give the client what they asked for rather than what you think they may want. How would the Owner use the life cycle cost data?
Since there is only one large transportation hub in Northern California in design I do not believe that the life cycle costs will significantly influence whether the project will be built. More likely they are concerned with initial cost and some assurance that the project will last a long time.
Again, thanks for your insights.
I think Mark suspects which project it is, even though I cannot name it in this forum, but his approach, may be the most logical and economical (for the design team); that is to write a report regarding the choices made during the material selection process with short, comparative studies of other options facing the design team.
Peter, your thoughts parallel mine, but we don’t have the knowledge, fee and experience to develop a data base of the life cycle cost for the choices already made; so we’ll try Mark’s approach and see it it flies.
you know, various manufacturers and trade organizations do have reports that they use as part of their selling. The California Cement Association (for example) has durability studies of concrete versus asphalt paving. A number of the steel panels will have accelerated weathering tests showing their materials versus other materials. (I do not know of one that addresses glass, however). All the sealant guys have studies with UV resistance and accelerated weathering.
Pulling this material together will probably never really pay off (i.e.: you will spend more time than you can bill for) but if you start with the trade associations I bet you can go a long way towards this idea.
I would go with Anne’s recommendations. As the Brick Industry Association we have various reports about the longevity of brick vs other wall systems. To show this, we conducted a life cycle cost analysis. This is certainly being talked about a lot in the construction industry, but I’m not sure how often it is really done on a formal basis.