I need some advice on a tricky situation. I manage a property where the kitchen sink is on an exterior wall on the second floor, and unfortunately, the pipe regularly freezes during really cold weather, which is common here in Montana. The exposed area is about 4 feet long before the wall meets the first floor. I thought about adding a closable HVAC vent under the sink to allow warm air from the heated space to flow into the stud bay and prevent the freezing problem. However, I just realized that cutting a hole for this vent would puncture the vapor barrier, which seems counterproductive since it's supposed to shield against airflow that could lead to mold or freezing. Relocating the pipe would be too costly and I really need to find a solution. So, is it acceptable to cut the vapor barrier to install the vent in this situation?
3 Answers
Puncturing the vapor barrier could allow moisture to enter the wall cavity, which isn't good news for avoiding mold problems. Instead of cutting it, perhaps look into insulating the pipes? It's not foolproof, but it can help slow down freezing. If you need something quick and effective, heating cables are a solid option too. They're affordable and only activate when it gets really cold.
Diving into the vapor barrier issue could lead to more problems with mold and moisture. Is there a way to insulate the pipe without compromising the barrier? Also, think about how your house is heated as losing heat this way can get pricey. Heating cables are a smart route; you can control them based on temperature with some basic tech.
Honestly, cutting the vapor barrier might not be the best move here. Instead, consider wrapping the pipes in heat cable, which you can find at home improvement stores. That way, you keep the barrier intact while protecting against freezing. I've seen good results using these and they aren't too difficult to install.