When it comes to construction projects, you're almost always better off calling a professional. Not only will the finished product look and work better, but you'll likely save money in the long term on repairs. 

However, these 23 people thought they could do an adequate job themselves, and put their DIY skills to the test with home, auto, and property "improvements." But unless they're blinded by hubris, we're willing to bet they'll be calling the professionals next time.