We recently purchased a home with a fully finished daylight basement. First winter here and all our bathroom pipes froze. They run along an exterior wall that has concrete exterior drywall and finished interior and nothing in between. I hired an insullation specialist who said to blow in cellulose but I have read that's a bad idea against concrete. We have to do something or pipes will continue to freeze. I have no construction skills myself so will have to hire out. I am looking for a fix that will stop the freezing without trickling water five months of the year and without mold growth. Any ideas?
Blowing in insulation would make matters worse along a concrete basement wall. First, cellulose absorbs moisture and there is probably no moisture barrier in the wall. Second, I would never put cellulose in a basement wall because of moisture issues. Third, insulating will prevent enough heat getting inside the wall to keep the pipes warm.
Short of moving the pipes away from the exterior wall (and I mean nowhere near the wall) and reconstructing the wall without the pipes within it, there is not much you can do except remove the drywall and keep the room above freezing temperature.
I lived in a house like this for a while. Everything was finished except the wall that had the pipes on it. It got cold in the winter and really wasn't much use. And on really cold days I couldn't even close it off or for sure the pipes would freeze. If you could not finish the wall with the pipes and insulate the pipes themselves, that might at least keep the pipes from freezing.
They sell electrical heating cable to keep pipes from freezing, but if someone sells that idea to you make sure your fire insurance is paid up. Not what you wanted to hear, but that's the best I have.