Product Review


Timbrex™ is Mobil’s new name for a product that has been around for several years under the name Rivenite. In 1992 Mobil Chemical Company purchased the Rivenite technology (hiring its developer, Roger Wittenberg) and formed a Composite Products Division to produce and market the material. Although Mobil is working on possible changes to the product, Timbrex is currently identical to the former Rivenite. Even Mobil’s glossy Product Information sheet is taken almost word-for-word from older Rivenite literature.

Timbrex is made by blending recycled plastic resins (primarily HDPE and LDPE) with sawdust from a furniture factory and extruding the mixture into standard lumber dimensions. Like plastic lumber, Timbrex holds up well in exterior use and doesn’t require any protective coating. The promise of a maintenance-free material only holds, however, if you like a light gray color, which is what Timbrex becomes after a few months’ exposure. The material does take paint and stain quite well if you want a different look (unlike 100% recycled plastic, which can be difficult to paint). Several contractors agreed that Timbrex looks and feels more like wood than does lumber made entirely from plastic, and it doesn’t tend to heat up in direct sunlight as do some plastic materials.

Published March 1, 1993

(1993, March 1). Timbrex. Retrieved from