It's unprofessional to install clapboard siding with anything other than even reveals. Gecko Gauges ensure nice even spacing between courses and make fiber-cement lap-siding installation 30 to 50 percent faster, says the maker. Used in pairs, the units clamp by friction to the top course of siding, providing a temporary shelf for the piece above. They can be adjusted to vary the coursing in 1/4-inch increments and are designed not to mar the face of the siding. Models exist for a number of James Hardie and LP SmartSide lap and drip-edge siding products.
Price: $65 per pair. 800-297-7487. www.pactool.us.