T he trend toward value engineering in building construction has been underway for years . In the plumbing industry we have noted the practice of re - placing originally specified cast - iron soil pipe and fittings with plastic drain, waste and vent (DWV) plumbing systems . The worst econo - my in 70 years tempts engineers, developers and contractors to look at this possibility to save every penny they can . On the surface, value engineering may ap - pear to be good business . Code restrictions on the use of plastic pipe and fittings have gradually diminished over time in certain model codes and local jurisdictions . And certainly there are appropriate applications where it makes economic sense to use plastic in place of cast iron – such as in tract home construction – because the purchase price of PVC DWV pipe and fittings can be signifi - cantly less than cast - iron pipe and fittings . But in our estimation, the practice of value engineering within the industry has gone too far and as the president of a company that manufactures both plastic and cast - iron pipe and fittings, I feel an obligation to speak out . There are applications where Charlotte Pipe and Foundry would not recommend the use of plastics as a replacement for cast iron – specifically in underground, commercial high - rise construction or high - end custom homes . Not only is it technically inappropriate in these applications, often it does not even make economic sense to switch . While others argue that plastics meet the minimum code standards, what meets code and what represents the best solution for high - performance buildings are two very different questions . When deciding whether to change a specification from cast iron to plastic, people too often overlook areas that can add cost and complexity to a commercial project when installing plastics properly – areas such as fire - rated construction, sound attenuation, crush and deflection under - ground, thermal expansion and contraction, and hangers and supports . Fire - Resistive Construction Today’s high - rise commercial buildings are constructed with fire - rated separations to contain the spread of flame and smoke . The critical juncture for plumbers is when fire separations are penetrated with piping sys - tems . For combustible materials such as plas - tic, these penetrations must be sealed back to the original fire integrity of the compartment with a fire - stopping system tested by a na - tionally recognized lab to ASTM E - 814 Smoke and Flame Spread test . Value Engineering Has Gone Too Far guest editoria l By Roddey Dowd, Jr . What meets code and what represents the best solution can be two very different questions . Note: The views expressed here are strictly those of the author and do not necessarily represent pme or BNP Media . Charlotte Pipe and Foundry does not recommend the use of plastics as a replacement for cast iron specifically in underground, commercial high - rise construction, or high - end custom homes .