How to Address Joint Leakage in GRC Exterior Walls? Qinglong GRC Joint Waterproofing Technical Guide

Treatment of GRC exterior wall joint leakage requires targeted measures based on the cause of leakage. Common treatment methods include: the grouting method (for crack leakage), sealant re-application (for aging failure), and the drainage method (for design defects). Before treatment, the leakage cause must be accurately diagnosed to select the correct remediation plan.

Grouting materials use epoxy resin or polyurethane grout, with grouting pressure of 0.3-0.5MPa; sealant removal width is 1.5 times the original joint width, with depth ≥10mm; drainage holes are set at 8-10mm diameter with 300-500mm spacing. At one project, joint leakage treated by grouting showed no leakage through the rainy season test, demonstrating good remediation results.

Leakage Cause Diagnosis

Determine leakage points through water spray tests, and analyze whether the cause is joint failure, improper node design, or material aging. If necessary, use an endoscope to inspect internal conditions.

Grouting Treatment Process

Grouting hole spacing is 200-300mm, grouting proceeds from bottom to top with pressure increased uniformly. After grouting, the surface is cleaned and leveled to restore the decorative effect.

Sealant Replacement

Remove aged sealant, clean the substrate thoroughly, and apply primer. New sealant thickness ≥6mm, width 1.5 times the joint width, application temperature 5-40°C.

Drainage System Improvement

Install water guide channels or drainage holes to ensure infiltrated water is discharged promptly. Drainage slope ≥5%, with drainage capacity meeting the maximum rainfall intensity requirement.

Joint leakage requires treating both symptoms and root causes. Correct diagnosis and a scientific remediation plan are the key to ensuring effective results.