We installed tile and carpet on the bottom floor oh our split entry home in New England. Tile is ceramic installed with metal schluter edge with the carpet installed with pad ad tack strips over the concrete slab.
Over the last several years, a chaulky white substance has formed at several points along the transition from carpet to tile. It doesn't appear to be mold or mildew as is is hard and dry but it does seem to be damaging the carpet.
The room is half below grade with no standing water/leak issues othe than any moisture associated with the concrete slab ( we run a de- humidifier and notice no musty odors).
Will try to attach photos...
Thoughts?