How often should exterior walls be cleaned? Safety guidelines for high-altitude cleaning operations

Glass curtain walls should be cleaned every 6-12 months; stone and aluminum composite panel facades can extend to 12-18 months. In coastal or dusty areas, reduce the cleaning interval. Pricing is primarily based on area: glass curtain walls range from 3-6 CNY/m², and stone facades from 5-9 CNY/m². Projects under 500 m² are typically billed at the minimum service fee. High-altitude work is a specialized operation requiring certified personnel. A safety exclusion zone must be established, with dual-rope protection and fall arresters required. Work must cease during winds of 5 Beaufort scale or higher, thunderstorms, or extreme heat. Before hiring, verify the following documents: business license (with high-altitude work scope), worker's high-altitude operation certificate, and employer liability or accident insurance policy.