There is no set time requirement between a rain event and the installation of the roof membrane. Your Roof Membrane Manufacturer and/or LWIC Applicator can give you a good time estimate on a case by case basis depending upon the amount of rainfall encountered. At the very least, all standing water should be removed from the surface and any seems, edges and/or the surface should be free of the shadow-like effect of absorbed moisture (the LWIC should possess the normal light grey color of dry concrete).
