Fill Cracks & Insulate
Metal siding is usually installed over the sides of wooden buildings that need repair. Metal siding is cheaper than repairing wood siding or installing new wood siding. Repair any large cracks or holes on the wood siding by filling them with expanding foam, which comes in an aerosol can. You can then either nail the metal siding right over the wood siding or, to insulate your building first, staple underlay right over the wooden siding. Your local hardware or home store will have siding underlay. Use a staple gun to attach the large squares of underlay right over the wood siding.
Installing Over Wood Siding
Mount sheets of metal siding starting from the bottom left corner across and then work up in rows. Place the first sheet of metal flush to the corner of the wall. Nail all four corners of the sheet down. Each metal siding sheet has ridges for strength. Find a low ridge near the center of a sheet of metal siding, nail down the middle on both ends of the sheet and along the center low ridge. Follow the diagram for a rough estimate of where to hammer nails into the piece of sheet metal. Space nails out by 1 to 2 feet apart. Use ring shanked nails (as pictured). If the last row of sheet metal siding doesn't fit you can cut it to size with a torch, plasma cutter or metal shears.
Installing on Steel Frames
Metal siding purchased to be mounted on a steel-framed structure will have pre-drilled holes around the outside of the sheet. You will start from a bottom corner of the structure and bolt the end of each sheet to the building frame. Once you get to the next row, continue to bolt them to the steel frame and also bolt the sheet tops and bottoms together.