All walks, drives and patios should be constructed to ensure proper drainage. Concrete sidewalks are normally flat, but walks made of brick, tile or paving blocks should have a slight crown built into them. The crown promotes drainage, minimizing the effects of the freeze-thaw cycle, and eliminates puddling.
Before laying a brick path, I use a wood screed with a slight arch to contour the sand bed. The screed has a notch cut into each end, as shown in the drawing. The notches, which are 1/4-in. shallower than the thickness of the brick I'm using, ride on the path's wood borders. Before I use the screed, I moisten and tamp the sand to minimize settling.
Rod Goettelmann, Vincentown, NJ