Benjamin Obdyke Put thousands of millimeter-tall bumps on its housewrap to create what it claims is a better version of the stuff. The bumps on HydroGap Drainable Housewrap enable water to drain from wall assemblies at least two times faster than from other drainable housewrap, the company says. It also maintains that HydroGap removes 100 times more bulk water than standard housewrap, thus reducing the potential for moisture and mold damage in wall assemblies. 800.523.5261.