My home is 11 years old. I have been noticing for the past few years that there are many places on the ceilings, on both first and second floors, where the dry wall seams are now showing as a raised bump in the surface. What causes this? The ceiling is finished in Monterrey(sp?) style--textured by scraping with a wide putty knife when partially dry for a fairly flat, but textured and patterned, appearance. Are these seam ridges indicative of anything that needs to be addressed? I don't believe there is an overabundance of moisture in my home, but we do live in a hot, somewhat humid climate (San Antonio) where the A/C is used a great deal. Is this a sign of the tape in the joints pulling away? Any comments anyone?