Typically, Diathonite plasters (Diathonite Thermactive and Diathonite Evolution) can be applied onto bare blockwork, brickwork or stone with no primer. A fine mist of moisture can sometimes assist with the initial key of Diathonite plasters onto the wall. For low-moisture absorptive surfaces such as timber, existing smooth lime plaster etc., then Diasen Aquabond primer must be applied.