Hi. We have discovered mildew all over the chip board floor in one of our rooms. The chip board is covered with underlay and carpet. The room is part of an extension only about 4-5 years old built by a previous owner. We don’t have access to the subfloor and there is decking around the house. No leak from pipes (tested) and storm water pipes seem fine. The chip board edges have been sanded down which seems a bit sus? At first we thought it might be condensation but could it be coming from the sub-floor?
Is it possible to get rid of the mildew? The underlay seems a bit stinky - should we replace or just air out? Appreciate your thoughts...