1 is 1.6. According to the latest Code for Acceptance of Construction Quality of Building Decoration Engineering in 2023, in order to strengthen the construction quality management of building energy-saving engineering and unify the construction quality acceptance of building energy-saving engineering, the external wall thermal insulation plastering bonding mortar must be mixed with 1kg powder and 1.6kg water, and the mixing ratio is 1 ~ 1.6.