所有建筑外立面都要刷防水涂料么

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。。听说还要找设计院。，还要报规划、城管、消防。

请问图中红圈里的水泥小平台是起什么作用的？

我家的墙面想要刷防水涂料，请问应该怎么刷，是跟刷一般涂料的方法一样吗？