Winter Exterior Wall Coating Construction Notice

With the arrival of winter and falling temperatures, Huike kindly reminds you to take proper cold protection measures while ensuring construction safety.

During winter, heavy rainfall, temperature drops, and strong winds occur frequently. Under such harsh weather conditions, exterior wall coating projects often face challenges that may affect construction quality and progress. The following outlines the basic requirements and key precautions for Huike coatings during winter construction.

Winter Construction Conditions and Requirements

1. Substrate Inspection and Preparation

Substrate preparation is the foundation of any coating system. It includes removing dust, oil stains, and loose materials from the surface, as well as reducing or eliminating surface defects. During winter construction, excessive substrate moisture and low temperatures may cause partial whitening of cement-based substrates. For newly applied plaster or mortar substrates, the curing period in winter should be no less than 14 days.

For Huike coating applications, a qualified substrate must meet five basic requirements: sound, flat, dry, neutral, and clean. For exterior wall coating construction, the ambient temperature must be maintained above 5°C, and the relative humidity should be controlled below 85%. Otherwise, construction is not recommended.

2. Putty Application

Before applying exterior wall coating systems, ensure that the substrate is completely dry and that the wall surface temperature meets the requirements. When daytime temperatures fall below 5°C, construction should preferably be carried out on walls exposed to direct sunlight. Working hours are recommended after 9:30 a.m. and before 3:30 p.m. For shaded walls, construction should be scheduled between 11:30 a.m. and 2:30 p.m., when temperatures are relatively higher.

Using Huike-compatible primers and putties can provide a more stable environment for exterior wall coatings and reduce the impact of low temperatures. During construction, judgments should be made based on actual environmental conditions. The next process may only proceed after the previous layer has fully dried.

3. Exterior Wall Coating Application

Before coating, confirm that the substrate or alkali-resistant primer is completely dry. The construction temperature must be kept above 5°C. At low temperatures, film formation becomes more difficult; therefore, multiple thin coats are recommended instead of one thick application. Special attention should be paid to shaded wall surfaces, which are more difficult to form a proper film during winter.

The mixing ratio and actual spray performance of exterior wall coatings and topcoats are significantly affected by winter temperatures and environmental conditions. Low temperatures slow down or even stop water evaporation within the coating film, which may lead to common issues such as irreversible whitening, soft films, or peeling. Once frozen, the coating film may suffer from reduced hardness, chalking, peeling, or softening. Therefore, construction must not be forced when conditions are unsuitable.

Winter Construction Precautions

1. Coating Storage

During winter, all coatings stored on construction sites should be placed indoors and stacked by category. Indoor temperatures must be kept above 0°C. When temperatures fall below 0°C, heating equipment or electric heaters should be used. Open flames are strictly prohibited. Unused coatings during construction must be stored indoors. Products that have been frozen must not be reused.

2. Coating Film Curing and Finished Product Protection

Under standard conditions of 25°C, coating films typically require 7 days to fully cure and achieve optimal performance. In winter, due to generally lower ambient temperatures, the drying and curing period will be extended accordingly. During this time, exposure to rain, snow, and smog should be avoided, and contact with water must be prevented. Efforts should be made to minimize contamination and mechanical damage to the coating surface, as repairs may affect the overall appearance.

Winter construction should include appropriate protective measures based on site conditions to prevent coating films from freezing, ensuring both coating quality and construction progress.

3. Control of Construction Quantity

When ordering customized coatings, confirm the required application quantity, construction schedule, and coated area in advance. Coatings should be used promptly to avoid prolonged low-temperature storage. Weather conditions should be closely monitored to prevent material loss caused by sudden temperature drops that make construction impossible.

4. Construction Planning for Low-Temperature Regions

In regions with relatively low winter temperatures, large-scale construction is not recommended. Prior to ordering, production quantities should be adjusted according to recent temperature forecasts. For projects in special regions, early communication with Huike is advised so that appropriate formula adjustments can be made during production. Before construction, it is necessary to fully understand whether site conditions are suitable and to clarify specific construction requirements and precautions.

5. Weather Monitoring

Due to frequent weather changes across different regions, weather conditions should be closely monitored during exterior wall coating construction. Construction is not recommended within 12 hours before or after rainfall.