What Is the Construction Process for Retrofitting Existing Building Facades with UHPC Panels? — Qinglong Group's Complete Guide to Old Building Renovation Technology

Renovating existing building exterior walls with UHPC panels is an important means of urban renewal, requiring a systematic process to ensure construction safety and results. Based on experience from multiple renovation projects, Qinglong Group has summarized a four-step construction process—inspection and assessment, substrate treatment, panel installation, and sealing protection—controlling the renovation cycle to 30-45 days, minimizing impact on building use, and achieving the renewal and upgrade of old buildings.

Inspection and assessment form the foundation of renovation. Through methods such as the tapping method and infrared thermal imaging, the condition of the original walls is comprehensively inspected, evaluating substrate strength, flatness, and leakage. In the renovation of an old residential community in Nanning, Qinglong Group used drones equipped with HD cameras for inspection, improving efficiency by 3 times. The inspection covers hollowing rate, crack width, and substrate bond strength to ensure the substrate meets installation requirements. For non-conforming areas, reinforcement plans are developed, such as leveling with polymer mortar or reinforcing with steel wire mesh, ensuring the substrate bearing capacity is ≥0.3MPa.

Substrate treatment critically determines installation quality. The original finish layer is thoroughly removed, defects are repaired, and flatness is improved to ≤4mm/2m. In the renovation of an office building in Shenzhen, Qinglong Group used mechanical roughening and high-pressure water jet cleaning to ensure the substrate was clean. Waterproofing treatment must not be overlooked; a penetrating waterproofing agent is applied to form a continuous waterproof layer. Precise positioning is achieved through measurement and setting-out using a total station, with errors controlled within ±3mm. These steps lay a solid foundation for UHPC panel installation.

Panel installation requires careful operation. A dry-hanging system is adopted with hanger spacing ≤600mm, allowing fine adjustment. Qinglong Group has developed specialized connectors to accommodate the unevenness of the original structure. Installation proceeds from bottom to top, with panel joint widths reserved at 8-15mm to accommodate thermal deformation. Joint treatment uses multiple sealing passes: foam adhesive filling on the inside and weather-resistant sealant sealing on the outside, ensuring watertightness. Through standardized construction, the renovated result is aesthetically pleasing and durable.