Damp Proofing

Salt / white crystals under floor board in grade 2 listed mid terrace house

Anonymous user 23/02/2024 - 2.47 PM

I live in a grade 2 listed mid terrace house, converted into 2 flats, and I live on the ground floor. Last year some of my bedroom furniture developed mould spores, only on the backing panel and underside of drawers. As I thought there was a problem in the chimney, as furniture was in alcoves either side of it, I had a survey done. There was no damp in the chimney and I have no signs of damp in the walls or anywhere else. A dropped joist was identified and has been repaired and the underground ventilation cleared as this had become blocked with stones etc, and I now use a dehumidifier in this room for 12-14 hours a day as the humidity was high. The room now has a better atmosphere and feels warmer. A year later and on looking under a floor board I have seen what I believe is salt crystals, it looks like white crystals. Is this from any damp drying out and what should I do next please? Do I need a specialist or do I need to wait longer? I live in the Wiltshire area and am finding it difficult to find anyone who deals with damp in older houses. Thank you for your response Joseph/plasterworks