Erik J. Weisskopf, ABR,CDPE,CRS,GRI
Re/Max Distinctive Real Estate, Inc.
The location of the 'dip' is necessary to determine what the cause may be. Is it near a water feature i.e. sink, tub, shower, toilet, etc.? There are structural engineers in the yellow pages, on the web, and possibly on Angie's List.
I recently had a buyer use one to check out the possibility of moving a stairway to a basement. They have different price points so call to get their information. Give them full details of the issue and photos too.
I hope this helps. You may contact me if you have additional questions.