Contractor Hidden Fees

[Mike Welch]

I'm in the midst of renovating a house to serve as a long term rental. I hired a contractor to put in a tile flooring with the look and feel of wood. The contractor gave me a bid that included 'Floor Prep' as a line item.

Now, the job is 90% complete, the contractor called me (I'm out of state) and told me that he had to level out the concrete floor in the living room in order to complete the install. He's telling me this will cost another $375 because it was more than he had planned for. In fairness, the area was carpeted before and he could not see what was under the carpet until it was removed.

The contractor did not inform me before beginning down this path. Now that he is almost complete with the project, he is presenting me with another unplanned expense.

How do you deal with contractors that introduce new fees during the project? Should I insist he complete this under his original 'order and sales agreement' (note: this is how he presented his bid, not as an 'estimate'). Should I simply pay the extra money and be done with it?