To the man in the street, the sidewalk is an everyday example of concrete work. Few products offer the concrete contractor a better opportunity to show what can be done with cement and aggregates. But, ironically enough, of all the things made of concrete, sidewalks too often seem to exemplify the poorest workmanship and the greatest neglect. The basic requirements for a satisfactory job are good materials and good construction methods. You must start with enough cement, a clean aggregate, and potable water, relatively free of deleterious foreign matter. Air entrainment is essential. Remove all sod and weeds from the subgrade. Fill the sink holes, then tamp the surface to a firm, level base. Stake the forms to hold them firmly to the line and grade. Reusable steel construction stakes can save time and money in forming sidewalks. Level the tamped surface with a stikeboard. Work with the strike board until the water glaze almost disappears. Fill any depressions with extra concrete. Contraction joints are separation planes between the slabs. As a rule, they are spaced at 5 to 6 foot intervals. To form a contraction joint, cut a groove across the newly placed walk to a depth of 1 inch. Use a T-bar to make the groove. Allow the concrete to stiffen, then withdraw the T-bar. Edge the joint by holding a double edger against the straightedge. It is just as important to cure the concrete in a sidewalk as in a highway. Membrane curing compounds are among the more convenient materials to use. The builder should make it his business to see that some type of protection is provided for at least 3 days.