Plaster dusty and not drying

[Plastereddom]

Ok so I’ve blue gritted a cavity block wall which was dot and dabed before and there is one wall outside wall that has not set formed a hard surface it’s still soy u can push a pencil into it i think this wall is a solid brick wall and is a cold wall compared to the other cavity insulated walls any advice would be grateful

 

[Dmac78]

Ok so I’ve blue gritted a cavity block wall which was dot and dabed before and there is one wall outside wall that has not set formed a hard surface it’s still soy u can push a pencil into it i think this wall is a solid brick wall and is a cold wall compared to the other cavity insulated walls any advice would be grateful

Hi. get a heater in there for a day