Q.: What's a highway straightedge? Is there anything to the claims that it makes floors less wavy? If so, does it increase the labor cost?
A.: A highway straightedge, also known as a paver's straightedge, is a long-handled, T-shaped tool in which the crossbar of the T is made of metal tubing. The tubing may be aluminum or magnesium with about a 2x4-inch rectangular cross section, preferably plugged at the ends. It may be 10 feet long or more. The tool is used much like a bull float, except that the leading bottom edge cuts or planes the surface, depositing the cut material in the low spots. Its great length improves the flatness of the surface, whereas the bull float is said to contribute to waviness. It does not seem to increase the labor time once the operators get acquainted with using it.