Great question—this is one of the first things landscape architects and city planners ask us when specifying street furniture for cold climates. Our urban benches are designed to handle extreme temperature swings, and freezing winters are usually the toughest test because they combine cold, moisture, ice, and road salt.
We treat a bench as a system rather than just a slab of material. A bench in Chicago might see -20°F in January and 95°F in July. That is a huge range, but the real damage usually comes from repeated freeze-thaw cycles rather than one cold night.
The first thing we control is frame material. Most of our benches use powder-coated galvanized steel or extruded aluminum. Galvanized steel is strong and, when finished with a marine-grade powder coat, resists both moisture and road salt. Aluminum does not rust and moves predictably with temperature, which makes it easier to design expansion room into the structure. We avoid unprotected carbon steel because it can become brittle and corrode quickly once the coating is scratched.
For seating surfaces, we often use high-density polyethylene lumber, thermally modified hardwood such as ash or oak, or aluminum slats. HDPE is popular in cold regions because it does not absorb much water, so it will not crack from internal ice formation the way some softer woods can. Thermally modified wood has much of its moisture and sugars baked out, making it more stable and less prone to rot. It still expands and contracts slightly with humidity, so we leave controlled gaps between slats. Aluminum slats are also common because they are light, strong, and can be anodized or powder coated for additional protection.
Thermal expansion is the detail that often gets overlooked. Metal and wood expand and contract at different rates. If everything is bolted down tightly with no room to move, panels can buckle, fasteners can shear, and welds can crack. Our benches use slotted holes and expansion gaps between deck boards. We also isolate different materials with nylon or EPDM washers to prevent galvanic corrosion and reduce friction noise during temperature changes. On long bench runs, we include movement joints rather than making one long rigid assembly.
Water is a bigger enemy than cold itself. When snow melts into a joint and then refreezes, the ice expands and can push components apart. To prevent this, we avoid closed box sections where water can collect. Frames are designed with drain holes or open profiles so moisture can escape. Any horizontal surface is slightly sloped or has a radius edge so water does not pool. Hardware is stainless steel, usually 304 or 316 near coastal or heavy salt environments, because standard zinc-plated bolts will rust and stain the bench within a few seasons.
We also test for these conditions. Our cold-climate benches go through thermal cycling tests from about -30°F to 150°F, plus salt spray testing to simulate road salt exposure. The finish must hold without cracking or delaminating, and all components must return to their original position after cycling. UV exposure is part of the same conversation because winter sun reflecting off snow can be surprisingly harsh on coatings and plastics.
In practice, a well-built urban bench should need almost no special winter maintenance. We do recommend inspecting benches in spring for scratches or chips in the coating. If bare metal is exposed, a touch-up paint or cold-galvanizing spray prevents corrosion from starting. Keep drain holes clear of leaves and debris, because blocked drainage is the fastest way to trap water and cause freeze-thaw damage.
So the short answer is: we select materials that do not absorb much water, allow them to expand and contract with gaps and slotted connections, protect metal with tough coatings, and design the bench so water drains away before it can freeze. That combination is what makes our urban benches genuinely weather-resistant outdoor furniture, able to handle everything from a mild frost to a deep-freeze winter without cracking, warping, or rusting.