Rip Rap is a larger rock that is often used for lining rivers, ditches, and streams. Typically, this is not bought by do-it-yourselfers or homeowners, but it does have uses for the homeowner. For example, Rip Rap can be used to redirect the flow of drainage or overflow where a water system can potentially damage a home or landscape.   1 Stop Landscape Supply’s Rip Rap is generally sold sized 6” – 12”.