How to Clean a Dirty GRC Surface: Practical Cleaning Methods and Precautions Explained

In the field of modern architectural decoration, GRC (Glass Fiber Reinforced Concrete), with its lightweight, high-strength nature and rich modeling possibilities, is widely used in exterior wall cladding panels, landscape components, and European decorative moldings for premium projects such as grand theaters, commercial complexes, and landmark buildings. However, long-term exposure to outdoor environments makes GRC surfaces prone to accumulating dust, stains, and even contaminant erosion, affecting the building's aesthetics and durability. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group combines detailed design, manufacturing, and after-sales maintenance practices to provide scientific GRC cleaning solutions for designers and owners.

### I. Types of GRC Surface Contamination and Pre-Cleaning Preparation GRC surface contamination falls into three main categories: daily accumulated loose dust and sand, water stains and streaks formed by rainwater runoff, and biological attachment (such as moss) or chemical corrosion (such as industrial exhaust) caused by long-term exposure. Before cleaning, a surface assessment is required: use clean water with a neutral pH for an initial rinse to observe whether the stains dissolve; for stubborn stain areas, Qinglong's GRC-specific test reagent may be used, avoiding strong acids or alkalis that could damage the material's surface structure. Meanwhile, prepare soft brushes (nylon is best), a high-pressure water gun (pressure controlled at 0.3-0.5MPa), and a dedicated neutral cleaner to ensure the tools cause no mechanical damage to the GRC surface.

### II. Practical GRC Cleaning Methods by Scenario #### 1. Routine Cleaning of Loose Dust and Light Stains For daily cleaning of building facades or landscape components, the "rinse + wipe" two-step method is recommended: first use a high-pressure water gun at a 45° angle to rinse diagonally, letting the water flow carry away loose surface dust; for residual light stains, dilute the neutral cleaner at a 1:20 ratio, gently scrub with a soft brush, then rinse thoroughly with clean water. This method is suitable for standard components such as GRC decorative moldings and sunshades, and can be performed monthly to maintain the material's original texture. Learn more industry information: +WeChat qlfsbl123

#### 2. Treating Stubborn Stains and Biological Attachment When oil stains, rust, or moss appear on GRC surfaces, targeted cleaning solutions are required. For oil stains, use a neutral cleaner containing surfactants (such as Qinglong's GRC-specific degreaser), let it sit for 5-10 minutes, then scrub; rust contamination requires a chelating rust remover to avoid acid products corroding the glass fibers; biological attachments such as moss should first be mechanically removed with a stiff brush, then sprayed with a diluted sodium hypochlorite solution (concentration ≤5%) for sterilization, and rinsed with clean water after 24 hours. Note during operation: rust removers and sterilizers must not be mixed, and after treatment, check the GRC surface for any color differences.

#### 3. Deep Cleaning in Special Environments In industrial zones or coastal areas, GRC may face chemical corrosion or salt erosion. Such scenarios call for a combined "neutral cleaning + protective reinforcement" approach: first thoroughly clean the surface with deionized water and a neutral cleaner to remove salts and chemical residues; once dry, apply Qinglong's GRC-specific protective agent (containing silane) to form a transparent protective film, enhancing the material's impermeability and weather resistance. This method can extend GRC service life to over 20 years and is particularly suitable for the maintenance needs of key projects such as airports and bridges.

### III. GRC Cleaning Precautions and Industry Standards Three principles must be strictly followed during cleaning: First, avoid hard tools such as steel wool or high-pressure sandblasting to prevent damage to the GRC surface texture and glass fiber structure; Second, keep the cleaner's pH between 6-8, prohibiting strong acids such as oxalic acid and hydrochloric acid, or strong alkalis such as sodium hydroxide; Third, promptly wipe moisture from gaps and joints after cleaning to prevent cracking caused by winter freeze-thaw cycles. As a participating drafting unit of the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), Qinglong Group reminds: GRC cleaning should be incorporated into the building maintenance system, with quarterly surface inspections and annual deep cleaning recommended to ensure the long-term stability of material performance and decorative effects.

### IV. Full-Chain Service Ensuring GRC Cleaning Results Leveraging its full-chain advantages in detailed design, manufacturing, construction installation, and after-sales maintenance, Qinglong Group provides customers with one-stop services from customized cleaning plans to on-site implementation. For large GRC projects, the company uses BIM technology to simulate cleaning paths and drone patrols to locate stained areas, improving cleaning efficiency; meanwhile, drawing on the R&D center at its production base in Nanning, Guangxi, it continuously optimizes GRC material formulations to enhance stain resistance. Whether for GRC exterior walls of real estate projects or landscape components of municipal engineering, Qinglong upholds the service standard of "meticulous workmanship, pursuit of excellence" to guarantee the lasting beauty of architectural decoration. Learn more industry information: +WeChat qlfsbl123