Construction preparation

1) The materials used in the building's external wall waterproofing project should be compatible with the relevant structural layer materials of the external wall. The performance indexes of waterproof materials shall all meet the requirements of relevant national standards after inspection.

2) The external wall plastering work should be carried out after the masonry construction is completed for at least 7 days and the experience is accepted.

3) Before plastering, check whether the positions of the embedded parts and reserved holes of the masonry are correct. The dust, dirt, oil stains, etc. on the surface of the substrate should be removed, and the crevices, holes and grooves on the wall should be filled tightly.

4) Before plastering, the masonry should be protected from rain or sun exposure. The surface of the masonry should be kept moist during plastering. The surface wetting depth of autoclaved aerated concrete masonry should be 10-15mm, and its moisture content should not exceed 20%; the moisture content of ordinary concrete small hollow masonry and lightweight aggregate concrete small masonry It should be controlled within 5% to 8%.

5) The oil stains and scum on the surface of the external wall structure should be removed, and the holes and gaps should be blocked and smoothed; the reinforcement treatment materials at the junction of different structural materials should be fixed firmly. The repair and leveling mortar should be the same as the mortar used for large-area plastering, and its strength grade shall not be lower than that of large-area plastering mortar.

6) When using dry mortar, the average total thickness of the plaster layer should not be greater than 20mm. When using ready-mixed or on-site mixing mortar, the average total thickness of the plastering layer on the exterior wall should not be greater than 25mm, and the average total thickness of the plastering layer should not be greater than 30mm for the external wall toe and protruding wall parts. Plastering should be done in layers. When dry mortar is used, the plastering thickness of the mortar should be 5-10mm per pass. When using ready-mixed or on-site mixing mortar, the plastering thickness of cement mortar should be 5～7mm per pass, and the plastering thickness of cement mixed mortar should be 7-9mm per pass. The last layer can be plastered after the first layer of mortar is set.