Yes, there is usually a weight difference, but it is not as simple as plastic being lighter or wood being heavier. In real-world outdoor furniture, a recycled plastic bench often weighs more than a softwood bench and lands in a similar range to many hardwood benches. The final number depends heavily on the wood species and the plastic profile design.
Recycled plastic outdoor benches are typically made from HDPE or similar recycled plastics. HDPE has a density around 0.93–0.97 g/cm³. That sounds close to water, but outdoor bench planks are usually thick, solid, or partly hollow profiles, so the finished parts carry real weight. A standard 6-foot recycled plastic park bench might weigh roughly 60–90 pounds, while larger or solid-profile models can exceed 100 pounds.
Wood varies a lot more than people expect. Softwoods like pine, fir, and cedar have densities roughly between 0.35 and 0.55 g/cm³. A 6-foot softwood bench may weigh only 40–60 pounds, which makes recycled plastic clearly heavier in that comparison. Medium-to-hard woods such as oak, teak, or eucalyptus range from about 0.6 to 0.85 g/cm³, putting them close to or slightly above HDPE. Very dense tropical hardwoods like ipe or cumaru can reach 0.9–1.1 g/cm³, so a bench made from those woods can actually be heavier than a standard recycled plastic bench.
Design matters just as much as material. Recycled plastic benches may use hollow or ribbed boards to reduce weight and improve drainage, while wooden benches are often built with solid slats. Hardware, frame thickness, armrests, and backrests also change total weight. Two benches with the same dimensions can easily differ by 20–40 pounds depending on how they are built.
Why does the weight matter? It affects stability, handling, shipping cost, and installation. A heavier bench resists sliding and feels sturdy, but it is harder to move and may cost more to ship. Recycled plastic’s weight is often seen as a plus because it adds a solid feel without the maintenance of wood. If you need a bench that is easy to relocate, look for lighter frames or thinner profiles. If you want a planted feel and strong wind resistance, either a dense hardwood or a solid recycled plastic bench will work well.
The bottom line: compared with softwood, recycled plastic benches are almost always heavier. Compared with dense hardwood, they can be similar or slightly lighter. Always check the actual product weight rather than assuming based on material alone.