During construction, there are many reasons that the Tyvek wrapping used is penetrated. It's unavoidable. The question becomes then, how can it be resealed? In this video, master builder, Matt Risinger shows how to flash a hose bib penetration behind siding prior to installation. The best way, according to Risinger, is to use a product called QuickFlash. It is the same panel that you see in a roof jack and a PVC pipe would be going through the flashing. The flashings have been altered them now for wall use, making it simple to install for all kinds of piping and hose bibs that come through the home's exterior. By slashing into the Tyvek and sliding the QuickFlash up into the slit, there's a 2" overlap. At this point, it's ready for taping. Using Tyvek flashing tape which is residential grade and tape the sides and the top. The bottom is left open for potential drainage. If installation is close to corners, just slice through the QuickFlash, install and tape.