I purchased my first home in December, a 50's ranch with a 90's second story. The issue we ran into during the long cold Ohio winter was a lot of pipe freezing in the addition, particularly the shower/tub. During the freezing incidents it was well below zero for weeks at a time so any reparation was unpractical and I settled for running the faucet to prevent further freezing.
I am no plumber or builder so forgive my lack of knowledge here, please. During the freeze I popped off the access panel to the plumbing and revealed the cavity beneath the tub. There was some blown in insulation on the floor but the rest appeared to be open entirely. I followed advice I found here at TOH and left the panel open with a heater nearby (with proper clearance etc), this eventually thawed the pipes but cooled the bathroom off terribly. I checked the temp in the cavity and it was 20 degrees F . Again, I'm a novice but that seems excessive. I placed some foam pipe insulation on the hot and cold pipes and continued the faucet running but I'm confident that won't be a permanent fix.
Where could this air be coming from and what should I do to fix it? I checked in the attic and it appears that my water pipes for the second floor are run through the gap between the two stories so they shouldn't be exposed to the attic temps. I've read elsewhere that there could be drafts following the pipe through a "wet wall" from the attic, if this is the case what do I need to do to cover it? Should I invest in blown in insulation around the tub and pipes? I'm completely unsure what I should do but I'd love to get it done now that we've entered the mild season.
Thanks for any suggestions.