Q.: We never heard of highway straightedges for floor construction until recently. Now the term seems to keep popping up. Are these tools meant to replace screeding tools, bull floats or what? What is the advantage, if any?
A.: The highway straightedge is a long-handled T-shaped tool. Its crosspiece is usually made of aluminum tubing of rectangular cross section, a shape that stays stiff and straight. The 90-degree edges of the bottom surface are sharp enough to provide some cutting action. The crosspiece can be of whatever length is needed, usually in the range of about 6 to 12 feet.
The tool is used right after strikeoff to straighten the slab in the long direction and is usually moved across the slab like a bull float. Where it is necessary to cut down humps, it is used with a jerky motion, but otherwise it is moved smoothly. It can also be used if desired after power floating or power troweling to remove some of the short waves that may have been introduced during floating and finishing.