What Is Foam Core Pipe?

Foam core pipe is a double-walled PVC pipe with a polymer foam injected between the hard plastic PVC walls.


It is available in a wide variety of diameters and has been in use for several decades, although research seeks to find new applications and variations for the material. Foam core pipe is used in construction, in similar fashion to single-walled PVC pipe. However, PVC piping with a foam core has particular advantages and disadvantages when compared to the traditional solid PVC pipe.

Foam core pipe is made by injecting a double-walled hard PVC pipe with a foam core. The foam is sandwiched between two layers of hard PVC plastic, and the center of the pipe is left open. The foam insides are made by combining PVC material with a blowing agent, which creates pores in the PVC.

About PVC

PVC is short for polyvinyl chloride, consisting of a polymer string of vinyl chloride monomer. It is a thermoplastic resin, meaning it re-softens when heated, as opposed to a thermosetting resin. This quality makes PVC an easy material to work with.

About Foam Core

PVC material is transformed into a foam consistency via a blowing agent. The blowing agent, azobiscarbonamide, is a yellow-orange powder that can be harmful if inhaled in its virgin form. However, when combined with PVC in the manufacturing process, the cellular structure of PVC is altered to create a new foam-like form.


Foam core PVC is lighter in weight than typical PVC piping. For this reason, it is easier to move and work with. Manufacturing and purchasing costs are lower than single-walled PVC pipe because less PVC material is used in their creation.


The uses of foam core PVC pipe are limited as a result of its light weight. The pipe cannot be used in high-pressure situations because of risk of bursting. Therefore, it is typically used in applications such as low-pressure waste-water transport and removal.

About the Author

Darci Pauser began writing in 2001. Her work has been featured in publications such as the "UC Berkeley Undergraduate Journal," Indybay and the West Texas Weekly. Pauser holds a certificate in sustainable agriculture from California's Green String Institute and a Bachelor of Arts in anthropology from the University of California, Berkeley.