Plumbing should always be looked at in the VE process, if for no other reason than there are a lot of units of pipe in a project. There are lots of places in a DWV system where value can be captured, but there are applications where what looks like value can mask risks that you might not want to take.
Because of financial realities, value engineering can often mean the difference between a project being shelved or a building being built. This creates tremendous pressure for VE practitioners to lower the first cost of any project. Often, this is a reasonable thing to do. The danger is that, when pushed too far, cost-cutting can add unacceptable risk, lower the value of the building and hide expenses in the total cost of ownership. That's what happened with the largest building project in recent NCAA history, the T. Boone Pickens Stadium at Oklahoma State University.
In 2011, two years after the Stadium opened, a break in a plastic drain pipe was found. An inspection of the rest of the system revealed 15 other breaks. The football team was forced to abandon the facility for five months while contractors jackhammered thorough concrete floors to fix the problems.
Litigation was eventually settled in February 2015, for $700,000. The biggest portion of the settlement ($400,000) was paid by the firm that did the architectural, engineering and design work. The manufacturer of the water heaters used in the renovations, agreed to pay $125,000 of the settlement. This suggests that the maximum working temperature of PVC was exceeded, leading to collapse and failure. Unfortunately, this avoidable mistake is more common than it should be.
PVC can be used successfully below ground, but it requires careful installation and soil prep per ASTM D2321. Further, if its maximum working temperature will be exceeded, it can't be used. PVC is only a value when it doesn't fail. To make value engineering DWV systems easier to understand, we have prepared a downloadable brochure and handy checklist.
At Charlotte Pipe, we make both PVC and Cast Iron pipe. We are proud of the products that we make with both materials, but it doesn't do anybody any good when a fine material is used in the wrong application. If you have any questions about value engineering DWV systems -- even if you aren't using our pipe -- please call Charlotte’s Technical Services Department at 800-438-6091.