This house was built in 2001 and is a slab house. We are the second owners. There is a mysterious musty odor that is in the foyer closet and in the wall from the foyer closet to the front door. The closet and foyer are back to back to the garage. We have had a mold/mildew inspection done and the results were negative. We have also had the water company come to check the meter (no problem) and inquired about a possible leak from the meter to the outside pipe to the road. Water Company person said there is no hissing sound so no leak. We have also had a plumber come and he could find nothing in way of a leak. We have also removed a small section of wallboard from inside the closet and there are no signs of moisture. We now have the foyer closet sealed with a plastic tarp as the odor is quite strong. If you sniff the walls in the foyer, the odor can be smelled.
Does anyone have any suggestions on what we can do next? Or even what this musty odor could be? I forgot to state that the water meter is located in the foyer closet.