Top list of the most atrocious things you've seen a contractor do

[Jon Shoop]

What is something that makes the top of the list for you of the worst thing that a contractor has done to a home improvement or home flip that you've experienced? 

When I bought my first home, it was for personal use. I found a great realtor who knew the DFW and Dallas area really well. She was absolutely fantastic. I wanted to stay on the Dallas side of DFW since I had buddies over there and had been living in Uptown. Fort Worth was attractive but I chose to stick around Uptown. So she and I toured all around East Dallas and Uptown Dallas checking out homes for sale that were in my price range. Many of these homes were needing a lot of work, some were needing a bit of work, and finally I got to a home that had just been remodeled and upgraded. It checked most, if not all the boxes. 

It was a flip house located between 75 and White Rock Lake, just north of the M Streets. I didn't have M Streets money! But it's a great location. It was being sold by a realtor who was getting paid $1,000 to facilitate the showings and deal by a company out of Arizona. 

Being a bachelor and my first home, I wasn't really looking too deep or was too nitpicky with it. I regret that decision. The general contractor the AZ company used was to put it bluntly, negligent. In the inspection report that we had done there were some fixes in the attic that needed to be made before it could be closed on. An open vent, a new attic access ladder, and a couple other minor things. 

What the inspection report missed and what I glossed over that still bugs me is the negligence that went into putting in the new windows. Apparently this GM and his crew didn't put down painters blankets or sheets to catch the old window's glass when it was broken out in order to install the new double pane windows. So there was countless amounts of glass shards strewn about the back and side yards in the grass, the dirt, and the hedges that have since been removed. 

That dang glass. All they had to do was lay down a large tarp to catch it all! Just such an easy thing to do yet so important to do. And ultimately so negligent on the contractor to not have done this. Absolutely grinds my gears. 

So BiggerPockets, what are some of your biggest gripes that you have regarding bad contractors?