1. Material Requirements

The materials used for cement mortar plastering must meet the following requirements:

(1) Cement should be ordinary Portland cement with a strength grade of P.O 42.5 or higher, and the mixing time should be controlled between 5 and 10 minutes;

(2) The mortar should be made from fine sand that meets building material standards, with a particle size of 0.1 mm or less, and should be free of dust and stones after drying;

(3) If other materials, such as fiber materials or additives, are to be added, they must comply with standards and pass inspection.

II. Process Requirements

The process requirements for cement mortar plastering should comply with the following:

(1) Substrate preparation: The surface of the substrate wall should be clean, firm, smooth, free of obvious cracks, and unevenness. It should be treated with cement mortar to seal dust and kept moist prior to cement mortar application;

(2) Mortar Mixing: Mortar should be mixed on-site prior to construction, with the cement-to-sand ratio controlled at 2.5:1, and adjusted appropriately based on the actual properties of the materials;

(3) Coating Thickness: The thickness of the coating layer should be controlled to 3 mm or more according to design requirements;

(4) Application method: Apply the mortar directly to the wall using a troweling method, ensuring it is applied evenly, fully, without holes, cracks, or bubbles;

(5) Surface treatment: After the mortar has initially hardened, the surface should be treated using methods such as fine scraping, troweling, or sanding. The surface should be smooth and flat, with consistent color, no color differences, peeling, hollows, or exposed substrate;

(6) Construction environment: Cement mortar plastering work should be carried out under normal construction conditions and should not be performed under adverse weather conditions such as high temperatures, cold weather, humidity, or strong winds and heavy rain.

III. Quality requirements

The quality requirements for cement mortar plastering primarily include the following aspects:

(1) Durability and strength: The plastering should be smooth and sturdy, with strength not lower than that of the base wall;

(2) Flatness: The surface should be flat and smooth, with no noticeable bulges, depressions, cracks, or slopes;

(3) No hollows: The surface should be full and solid, with no hollows, cracks, peeling, or flaking;

(4) Moisture-resistant and waterproof: The plastering should have good moisture-resistant and waterproof properties;

(5) Uniform color: The color of the plastering should be uniform, with no color differences or stains.