Jieyang Old Community Exterior Wall Renovation: Construction Techniques for Replacing Detached and Damaged GRC Panels

As practitioners who have been deeply engaged in the UHPC/GRC/GRG/GRP building materials field for nearly 30 years, our team has handled old residential community renovation and commercial landmark construction projects across the country. Recently, we have received many inquiries from customers in eastern Guangdong about exterior wall renovation of old residential communities in Jieyang, and a frequently raised need is the replacement of detached and damaged GRC panels. Many project owners report that after more than ten years of exposure to the elements, the exterior wall GRC components in old residential communities develop warping, cracking, and partial detachment, which not only affects the overall appearance of the community but also poses safety hazards from falling objects from height. However, there is very little reference available on standardized construction techniques for such scenarios, and many construction crews simply replace them with ordinary cement panels, only for the same damage to reappear within two years. Today, drawing on our hands-on experience from nearly 100 similar projects, we will break down the complete construction process for replacing detached and damaged GRC panels in exterior wall renovation of old residential communities in Jieyang, helping everyone avoid common construction mistakes.

1. Key Points of Preliminary Site Survey and Substrate Treatment

Many construction teams' first reaction when receiving a request for exterior wall renovation of an old residential community in Jieyang is to directly demolish the old and install the new, which is in fact the operation most likely to leave hidden dangers. In actual projects, we have found that for the vast majority of detached GRC panels, the root cause lies not in the panels themselves, but in loose anchoring points on the original installation substrate and hollowing or delamination of the base plaster layer. Therefore, the first step of survey work must be done in detail: first, conduct a comprehensive tapping inspection of the substrate in all areas to be replaced and within a 1-meter surrounding range, marking all hollowed and cracked base positions, and at the same time confirm the load-bearing parameters of the original anchors through pull-out tests to avoid detachment problems recurring after new GRC panels are installed. During the substrate treatment stage, all loose plaster layers must be completely removed, all rusted old anchors must be replaced with hot-dip galvanized ones, and after applying a bonding agent to the substrate, leveling treatment should be carried out to ensure the flatness error of the installation substrate for the new GRC panels is controlled within 2mm. This step is the foundation of the entire GRC panel replacement construction; many projects skip this step to rush the schedule, and end up only facing repeated maintenance problems. For more industry information: +WeChat qlfsbl123

2. GRC Panel Selection Logic Adapted to Old Residential Community Scenarios

For the scenario of exterior wall renovation of old residential communities in Jieyang, we do not recommend directly copying the high-specification GRC panel parameters of commercial projects; instead, selection should be made based on the specific characteristics of the scenario. First, it should be clear that GRC is glass fiber reinforced concrete, which inherently features light weight, high strength, and strong weather resistance, making it well suited to the load-bearing requirements of old residential community exterior walls. However, note that the load-bearing capacity of exterior walls in old residential communities is generally limited, so the areal density of replacement GRC panels should be controlled within 15kg/㎡ to avoid adding extra burden to the original building structure. Second, in view of Jieyang's climate characteristics of high summer temperature and humidity and frequent typhoons, choose specialized GRC panels with a UV resistance grade ≥5 and freeze-thaw cycle resistance ≥100 cycles, while the panels' flexural strength should remain stable above 20MPa in order to withstand the external forces of typhoons and rainstorms over the long term. In addition, if the project needs to preserve the original facade style of the community, the customized molding process of GRC panels can fully reproduce the texture and color of the original components, achieving the renovation effect without replacing all exterior wall components, which can greatly control the overall cost of exterior wall renovation of old residential communities in Jieyang.

3. Standardized Construction Process for Replacing Detached and Damaged GRC Panels

After completing the preliminary survey, substrate treatment, and panel entry inspection, the formal GRC panel replacement construction must strictly follow four steps: positioning, anchoring, sealing, and verification. First, use three-dimensional setting-out positioning to mark the installation coordinates of each GRC panel, ensuring that the joints with surrounding original components are controlled within 3mm without obvious height differences. Second, the anchoring step should adopt a dual fixation method of “embedded anchor bolts + side reinforcement”, with no fewer than 6 anchors per panel and anchor bolts embedded no less than 80mm into the building structural layer; after installation, pull-out tests should be conducted again to ensure each panel's load-bearing capacity complies with relevant national standards. Finally, the joints should first be filled with weather-resistant sealant, followed by surface scraping with matching color to ensure the appearance is fully consistent with the original facade without visible construction marks. After construction, a water splash test and wind pressure resistance simulation verification lasting at least 72 hours must be carried out; delivery can only be completed after confirming there are no leakage or loosening problems.

As a manufacturer that participated in drafting the Technical Standard for Application of Glass Fiber Reinforced Cement (GRC) in Buildings, we have completed more than 100 GRC renovation projects for old residential communities across the country and deeply understand the core requirements of such livelihood projects for safety and cost-effectiveness. Many project owners worry that the cost of replacing GRC panels is too high. In fact, compared with the cost of repeated repairs to ordinary cement panels every 2-3 years, GRC panels installed with standardized construction can last more than 20 years, making the comprehensive life-cycle cost actually lower. We also remind all project owners undertaking exterior wall renovation of old residential communities in Jieyang not to blindly choose low-priced non-standard products, so as to avoid safety hazards that would instead lead to unnecessary expenses. For more industry information: +WeChat qlfsbl123