Plumbing News

CPVC plastic pipe performs in multifamily construction

Working with CPVC piping differs fundamentally from working with copper and other plastic piping systems on several levels.

In an increasingly competitive multifamily housing construction market, property developers and contractors are looking for ways to save time and money. As the market continues to heat up, and as new technologies continue to gain ground within it, it’s an ideal time for contractors to investigate alternative material options.

Hookset, N.H.-based Armand E. Lemire Co. recently discovered the benefits of chlorinated polyvinyl chloride piping while completing a 26-unit housing complex in Nashua, N.H. Using CPVC piping as its material of choice to outfit the complex with plumbing, the mechanical contracting firm realized several benefits plastic piping brought to the table. Because the project went smoothly, the company plans on using the material again in larger and more involved projects.

Working with CPVC piping differs fundamentally from working with copper and other plastic piping systems on several levels. With the proper training, time and costs can be slashed with the knowledgeable installation of CPVC.

“It takes much longer to prepare for the job if you’re using copper,” says Jim Dooley, project manager for Armand E. Lemire Co. “The process with CPVC proved to be faster and neater.”

Much of it is due to the fact that CPVC can be fitted on site, without requiring prefabrication. As many contractors know, the fabrication of copper piping takes careful design and several weeks to be completed before the materials can be installed on the jobsite. In contrast, those working with CPVC can install the material on an as-needed basis.

This can be beneficial if the plumbing installation must be performed simultaneously with other trades or if an HVAC system has already been installed. The flexibility of a CPVC installation helped the Armand E. Lemire Co. save time on the housing complex jobsite.

Solvent welding

The key to a smooth installation is the solvent-welding process that is used to join CPVC pipe and fittings. Proper solvent-welding techniques help maximize the useful lifespan of a CPVC system. When performed properly, a solvent-welded joint becomes the strongest part of the system. To ensure the process was performed correctly, contractors with the Armand E. Lemire Co. were provided with specialized training by Lubrizol CPVC’s piping systems consultants prior to the installation.

Solvent welding is a cleaner, simpler and faster process than the soldering or welding of copper piping. While common industry perception misconstrues the use of solvent cement as a process analogous to gluing, the true science behind solvent welding is a more complex and dependable process.

Traditional welding requires heat, where solvent welding is a chemical reaction between the CPVC pipe and the solvent cement — a chemical weld. Solvent welding physically fuses the pipe with the fitting, forming a strong bond.

Several environmental factors should be considered to ensure the proper conditions for solvent welding, such as heat and humidity. Under increased heat conditions (above 90º F), solvent cement becomes less viscous, which may cause it to drip, wasting product and becoming inconvenient to use. Extreme temperatures also can cause the cement to dry more rapidly than is desired, requiring plumbers to work faster. Additional education may be needed for these circumstances.

Increased humidity, meanwhile, can have the opposite effect. Under extreme humidity, solvent cement becomes thicker and will not spread as easily or evenly as it should. The increased moisture in the air also may cause a lengthier set-time for the pipe and fittings, forcing plumbers to wait longer before handling the joint. Specialized solvent cements engineered to withstand extreme conditions are available. Plumbers and contractors are recommended to investigate which solvent cement best suits the application before beginning a project.

Be careful of dry fit

Throughout the housing complex installation, installers were instructed to avoid dry fit. Although infrequent, dry fit occurs when a plumber simply forgets to solvent weld a joint.

While this is a simple and easily avoidable error, it is important for everyone involved in the project to keep close tabs on piping joints. For example, a plumber may assemble a piping joint to check for proper measurement or to ensure the pipe and fitting fit together properly, but then may forget to disassemble the joint to apply solvent cement to complete the solvent-welding process. The result is a rogue, unwelded joint that may get lost among the dozens of joints across the entire housing complex.

“It can be easy to lose track of which pipe has been welded,” Dooley says. “In my experience, that is when you can lose continuity. I’ve performed pressure tests where a dry-fitted pipe has held together without leaking. It’s only after expansion, contraction and the addition of steady water pressure when they may blow apart — that’s when you find the fitting that wasn’t correctly welded.”

Specialized UV-indicated solvents, which are visible under black light, are available, allowing for a quality-checking step after the piping has been installed. Armand E. Lemire Co. plumbers utilized this method to ensure no pipe throughout the construction process had been mistakenly fitted without solvent cement. The Nashua housing complex is one of the first major construction jobs in which Armand E. Lemire Co. worked with CPVC throughout the project. As such, Dooley describes the project as a “prerequisite” — if the job proved successful, the firm would be comfortable using the material in larger projects moving forward.

And indeed, soon after the Nashua project, the contractor landed a lucrative mechanical and plumbing project with the Scott-Farrar Home, an assisted-living facility in Peterborough, N.H. The mechanical portion of the project, valued at $2.75 million, began this summer and will feature CPVC piping systems throughout the facility.

FlowGuard Gold pipe and fittings were used in both projects. Dooley explains that Lubrizol CPVC’s piping systems consultants proved to be valuable resources for his installers throughout the projects, offering expertise on working with the material, helping solve problems and providing the proper training on solvent-welding techniques.

Additionally, the company’s crews took advantage of Lubrizol CPVC’s unique FBC System Compatible Program throughout the job. The chemical makeup of CPVC piping can, in certain cases, interact poorly with other common construction products that the piping may come in contact with on the jobsite.

Available on the Lubrizol CPVC More Inside smartphone and iPad app, the program provides contractors with a frequently updated database of ancillary products that are safe to use with CPVC, as well as a list of products known to be chemically incompatible with the piping.

CPVC continues to grow in popularity and acceptance in the plumbing industry, particularly within the multifamily housing market. As plumbing contractors grow their businesses in this segment, it’s important for them to be knowledgeable about the use and installation of CPVC, and it’s vital to have access to a trusted and experienced partner.

Author bio: Mark Lemire is a Lubrizol CPVC piping systems consultant who has been with The Lubrizol Corp. for nine years. He educates the industry on Lubrizol CPVC brands, including FlowGuard Gold pipe and fittings, BlazeMaster fire sprinkler systems and Corzan industrial systems. Lemire also serves as a field expert, providing building professionals on-site training and expertise.