Water repellent primer for application to plaster, cement and plasterboard. Used as pre-treatment of surfaces before application of Hidroflex occurs. When the primer has dried, it is both water-repellent and elastic. Should be ironed in two or three layers. Access: approx. 300 g/m². Apply with brush or roller. For indoor use. Included in Biltema's wet room system. Note! Primer F should never be used with spring drum foil 86-664 or 86-665.