If you’ve experienced heavy rain, flooding or water damage in the home, mould can begin to grow and spread in as little as 48 hours. Off or damp smells often present in and around the home before any visible signs of mould appear. If the smell is localised to one room or area, check for any damp surfaces, ring-shaped water marks or leaks behind walls, ceilings or roof spaces. Other signs may include bulging or cracking paint on the walls or a noticeable discolouration growing through surfaces.