Hired a contractor for kitchen remodel. Contract includes putting in new subfloor & hardwood floor. New floor is in, and there is now a 1/2" gap between floor and door frame. Contractor suggests 2 fixes: install new frame, or install plinths on this frame and 2 others in the kitchen. He's expecting me to pay. Interested in knowing people's thoughts on whether I should be expected to pay for the fix. Seems pretty obvious that the subfloor he put in is not as thick as the one he took out. Is this a problem he should have seen coming and avoided? Is it just one of this things, and reasonable that I should cover the cost?