Earlier this month, through an auction, we have purchased a SFH in New Carrollton, MD that was built in 1959. The original owner died and we have no way of asking them about this problem. The house had been closed and "winterized" for 7-8 months prior to the auction.
We have a problem with the walls and ceilings in all of the rooms except for the Kitchen and the Bathroom. In some rooms this "phenomenon" is much more pronounced, in others, it is not as noticable. It is affecting all walls to some degree. The surface of the walls have a rectangular checker-board effect (that is visible and can be felt) of wide raised "peaks" and narrow "valleys". The rectangles are 16" high and 4' wide and create an interlocking "brick-like" pattern.
We have cut a hole in the wall of a closet to look through at the inside/back of one of the walls where it is most noticeable. The walls seem to consist of 4' wide by 16" high sections of wallboard/sheetrock/plasterboard/drywall. (I don't know the difference between these terms...are they all descriptions for the same thing?) They appear from the back to be finished on the edges. Over these strips is a fairly thick coating of plaster/spackle to cover the seams and the entire wall. These are the original walls, only the original owner before we bought it.
I am attaching pictures here to help show the problem with some "photoshop" lines added to emphasize the rectangles.
Does anyone know what causes this? Suggestions on what to do to get rid of the problem?
Thank you in advance!