DIY = "Did it yesterday" There is a water spigot just outside my laundry room, at the corner of the house. My ultra-conservative boyfriend turned it off, which made the pipe freeze and split just under my kitchen sink between the floor and cabinet base during the last freeze - HUGE mess. Now, there is mold growing on the drywall in the utility room, and since I'm not living in the house, and I don't get a chance to work on it every day, I only just noticed it. The mold was growing around two exterior walls inside the laundry room. (There isn't anything hooked up in that room at the moment, and no sign of water leaks from the faucets.) I've cleaned the mold off with bleach and water, and opened the windows to air out the house. Behind the drywall is tongue & groove, 2x4 studs and exterior lapboard. There is no insulation. I know I'll have to cut out and replace the drywall, but if there's mold growing inside the house, then there's going to be mold behind the tongue & groove, right? When I cut out the drywall, and clean off the wood behind it, is there a retardant I can apply to the wood before replacing the drywall? Also, I am going to remove the exterior lapboard, and see how much damage is behind it, while I've got it off, I am going to insulate. My next question: Is exterior lapboard/vapor barrier/insulation/drywall the correct way for insulating the sides of the house?