Damp Proofing

mould in communal hallway - New build

Anonymous user 23/02/2024 - 3.20 PM

In one half of the ground floor communal hallway in a new build (just turned 4 years old), we have very bad mould, black spots across all the walls, which has spread over time. For some reason this only affects the back half by the back door way, the front area by the front door is unaffected. I open the door and let air circulate whenever possible in that area, in contrast the front door is the main street entrance so this is always locked shut. I was wondering how you could explain that one half of the hallway has very back mould while the other does not? I expect the builder has not put in adequate vent holes in the back. What can be done to stop it and prevent it returning, is this work likely to be costly, and should this be undertaken by the builder? I also note that the mould affects some of the ground floor flats, despite following condensation/ ventilation advice. Many thanks for your help