My kitchen countertop (with intregal backsplash) has progressively separated from the drywall. We think it is from the drywall swelling during the winter from (what we suspect) is a lack of moisture barrier as this wall it also an exterior wall. This also happens with our master bathroom counter top. It too has an intregal backsplash pulling away from the drywall which swells during the winter, and is an exterior wall.
Suzzanne ~ Warrensburg, Missouri
Suzanne, I'm a little stumped by the problem that you are having with your counter top backsplash, because if the adjacent drywall is actually swelling due to moisture problems, then I would not expect the counter top to separate from the wall. Although drywall can swell when it gets wet, it doesn't often shrink noticeably when it dries, and you might expect a shrinking (or similar type of movement) to cause a backsplash to separate from a wall.
In my experience, when a backsplash separates from a wall, it is usually the caulking that has shrunk and exposed a gap between the two that has existed since the counter tops were first installed. With new construction I have also seen walls that move a little as the wall studs dry. That can cause a gap between the wall and the backsplash to open up, which in turn separates the bead of caulking that was hiding the gap in the first place.
Obviously, it seems that either your walls or the counter tops have moved just enough to open up the gap between the two, and I wonder if your home's floors might be sagging or settling, which could account for why your counter tops are no longer level. The fact that you are experiencing the same problem in the master bathroom is very odd as well, and unfortunately without knowing the floor plan of your house, it is difficult for me to connect the two problems with a common culprit.
You are correct in assuming that a new bead of caulking is your best cosmetic fix at this point. I would then have a contractor who works in the Warrensburg area inspect your house for clues as to what might be causing these problems. A thorough inspection of the walls and floor can help determine if this is a structural problem, and if so, how best to fix it. I would also have the contractor check for other signs of moisture problems within the wall, which might be some damage to the exterior siding or peeling paint on the interior side of the wall. Site-specific house problems such as yours are often mysteries that are best solved by careful inspection of the entire house, and often it requires the skilled eyes of a qualified contractor to gather all the necessary clues in order to solve the problem.