Galvanized steel is steel that has been treated with a rust-resistant zinc coating. It can come in the form of sheets, tubes or rolls, and is available in a variety of thicknesses and strengths. This material is used in manufacturing around the world for products exposed to moisture and adverse weather conditions. Some examples of its use include automobiles, building materials, fencing, and household appliances. The construction industry is one of the greatest consumers of galvanized steel products. This material has been used for support beams, piping, heating and air conditioning duct work, barriers and handrails. Metal roofing is popular in some regions because of its durability, rust-resistance, and ability to withstand extreme weather conditions. Unlike asphalt shingles, metal roofs are not easily damaged by hail and heat. It is lightweight, fire-resistant, and recyclable and basically maintenance free. In the past, most homes used galvanized steel pipes for water lines. This is no longer the case, since minerals in the water can build up and clog the pipes. Some piping is still available to replace parts in older plumbing, but currently these steel pipes are most often used for handrails and support pipes for metal fences, canopies and awnings. Steel tubing is also used to make chain link fencing. Houses built in climates which experience large amounts of snow or ice are more likely to have gutters made from steel than vinyl or other alternative materials. Steel gutters are stronger and more durable, making them less likely to bend or break from the weight of winter precipitation. Strainers and screens made from steel are also available to prevent leaves from filling the gutters, eliminating the need for regular cleaning. Steel buildings are relatively low-cost construction options. They are strong, yet much lighter in weight than traditional building materials, so have a lower foundation load. Most steel buildings are prepared to accommodate any exterior finish material desired, so the building can blend in with the neighborhood architecture. The automobile and aircraft manufacturing industries are also large consumers of this material. Sheets of hot dipped steel are used for the roof, seats, parking brakes, oil pans, and spring housings. Deep drawing steel is ideal for hoods and fenders. One advantage of this lightweight material is that it can be cut and shaped by the end user during the manufacturing process. Galvanized steel is used to make outdoor grates, which are available in a variety of sizes and can have either smooth or serrated, slip-resistant surfaces. These are frequently used for industrial walkways and road grate covers. Galvanized sheets are also used in electronic appliances, computers, and precision instruments. Other everyday items that can be made from galvanized steel are lights, beds, washtubs, bath tubs, buckets, and planters. Backyard grills and garbage cans are often made from steel. Playground equipment such as swing sets, jungle gyms, and bicycle racks are usually constructed from this rust-resistant material as well.