Seal those penetrations
Here’s a handy product that could help you keep rain water on the outside of the house where it belongs. WRBs work great at keeping bulk water out of a wall assembly. But if you punch a hole in the envelope for a pipe, vent or gang box, all waterproof bets are off. QuickFlash is designed to work in conjunction with a WRB to seal those problematic penetrations.
It basically works like a rubber roof vent collar designed for roof penetrations except the rubber on the QuickFlash panels doesn’t get beat up by the UV rays of the sun, which should make them last a long, long, time. Plumbing, electrical and HVAC panels are available in all sorts of sizes and configurations. Most cost under $10. Go to quickflashsproducts.com for more information and to buy.