The previous owner of my house converted the attached garage into a bathroom. They did a poor job; I live in Minnesota and it's always very cold in the bathroom. When the temperature drops very low the hot water pipe freezes, but the cold doesn't. The bathroom floor is on joists that sit on the old garage slab and there's no insulation between the slab and the bathroom floor. There is a small electric heater under the floor but it isn't enough when it's really cold. It has a small access panel in the hallway outside the bathroom, photo linked. I am wondering what the best option to insulate a little to help prevent frozen pipes again.I don't think I'll be able to get rigid insulation in because the access panel is too small. I could just put pipe insulation on the pipes, or I could put fiberglass insulation in the space. If I do this do I need to worry about condensation? Should I also put down a vapor barrier between the slab and the insulation?Everything I find online about insulating under floors or over concrete slabs recommends putting rigid insulation down during the construction phase, but this is not possible for me because I only have a small access area. I'm really not sure if fiberglass insulation would help or just make things worse by freezing condensation.http://ift.tt/2CledDI via /r/DIY http://ift.tt/2zZFdCF
