What is the allowable range of flatness deviation for GRC exterior walls?

Flatness deviation of GRC exterior walls directly affects the building's appearance and installation quality. According to industry standard JGJ/T423-2018 and Qinglong Group's engineering practice, the flatness deviation of GRC panel installation should be controlled within: panel surface flatness ≤3mm/2m, joint height difference ≤1.5mm, and overall facade verticality ≤H/1000 and ≤20mm.

Panel surface flatness is a fundamental indicator. When checked with a 2m straightedge, gaps must not exceed 3mm. Qinglong Group ensures that panels leaving the factory meet flatness standards by optimizing mold precision (±1mm) and production processes. During installation, a laser level is used to control elevation, with a hanger adjustment range of ±5mm, meeting installation requirements for different substrates.

Joint treatment affects the visual effect. The height difference between adjacent panels is controlled within 1.5mm to avoid noticeable misalignment. Qinglong Group adopted a dedicated leveling system in the Shenzhen project, achieving precise panel surface alignment through fine-adjustment bolts. Joint width deviation is controlled within ±1.5mm to ensure overall aesthetics.

Facade verticality guarantees the overall effect. Checked with a total station, verticality deviation must not exceed 1/1000 of the height, and the total deviation must be no greater than 20mm. In large-area curtain walls, control lines are set for segmented inspection, with installation errors adjusted promptly. This strict flatness control ensures the high-quality effect of GRC curtain walls.