Having a very detailed contract with your remodeling contractor cannot be emphasized enough! Pay special attention to the “change order” section, the “subsurface issue clause” and the “scope of work” proposed.
A reputable and experienced remodeling contractor will know most of the potential issues that might be uncovered when opening up walls, and will build a little extra in to the quote to deal with these issues so they can provide honest pricing.
Obviously, if we open up a wall and it is infested by termites or mold, this will be an unforeseen circumstance and will require action that will be more costly than anticipated.
It's the less reputable contractors you hear all those stories about. They will “demo” your construction area knowing full well that there will be an extra charge for what they discover so you get an expensive change order for the additional work.
The most common areas where this technique is abused is in soffits and opening up center walls for pass-troughs from a kitchen. We as contractors know full well that there are probably mechanical systems that will need to be moved, and it should be either checked ahead of time, or at least anticipated.
Always ask your prospective contractor to at least weigh in on what might be behind the walls that will require extra cost. It's sad that you have to educate yourself so much in advance, but unfortunately, not all contractors are willing to be honest with you.
Sometimes, we do run into the unexpected. Life is like that and home remodeling gets its share of surprises. However there are many things that are “typical” and any contractor that doesn't warn you of the possibility of extra charges PRIOR to signing the contract is either dishonest or inexperienced.
Always discuss sub-surface issues, and how they are handled, prior to signing a contract.
