laundry/water heater closet waterproofing

I have a 7.5′ wide x ~34″ deep closet space along the hallway at the top of my stairs for my water heater & washer/dryer. I’d like to waterproof the floor… I have a 7.5′ wide x ~34″ deep closet space along the hallway at the top of my stairs for my water heater & washer/dryer. I’d like to waterproof the floor…Read MoreGreenBuildingAdvisor