Many are looking for ways to cool their home on very hot days, but does spraying the roof of your house really cool it down? But does spraying your roof down with water really cool down your home? Does Spraying Roof Down With Water Cool House? In short, the answer is yes; spraying water on your roof can help cool the attic on a very hot summer day. And while spraying your roof with water may help cool your house, there are some drawbacks.