External Wall Sealing
Exterior wall sealing begins with a thorough substrate inspection to locate cracks and capillary paths that let water migrate into the structure. Cracks near windows, balconies, and connection joints require timely sealing to prevent water ingress. Choosing a compatible coating or membrane is key, as different substrates demand different levels of elasticity and adhesion.
For exposed walls, high-performance elastomeric coatings or cementitious membranes form a flexible waterproof layer that resists cracking. Detailing around downpipes and sill flashings prevents rainwater downpipe leakage by stopping water at shared joints. Surface preparation, including cleaning, degreasing, and roughening, ensures the waterproof layer bonds properly.
Downpipe Leakage
Downpipes route roof rainwater to the drainage system and are a leading source of exterior leaks when joints deteriorate. Common failure points include elbow connections, flanges, and penetrations through walls where water can seep behind finishes. Assessing the downpipe network on a regular basis helps catch corrosion and misalignment before interior damage occurs.
Repair options range from gasket replacement and sealing tapes to re-glazing joints with appropriate mastics. When leaks are persistent, rerouting or upgrading to thicker, corrosion-resistant materials can reduce future maintenance. Integrated system checks, including evaluating the wall interface and its waterproof backing, are essential for long-term performance.
Rainscreen Design
Rainscreen design creates an air gap that improves drainage and reduces moisture buildup on exterior walls. Selecting water-resistant cladding, proper furring, and continuous drainage layers helps channel water away from the structure. Attention to detailing around doors, windows, and heavy fixtures is crucial to prevent capillary wicking behind the cladding.
Modern rainscreen systems use breathable membranes and capillary breaks that balance moisture management with vapour diffusion. Proper installation requires precise alignment of the weather barrier with the cladding and rain screen to avoid hidden pockets. Regular inspections of joints and sealants in the cladding system prevent early-stage leaks from becoming costly repairs.
Maintenance for Externals
Preventive maintenance keeps exterior waterproofing effective for years by catching wear before it becomes a leak. Schedule seasonal inspections of balconies, parapets, and roof edges where water tends to accumulate and degrade sealants. Clean debris from gutters, downpipes, and drainage paths to prevent blockages that force water onto vulnerable wall interfaces.
Repair schedules should prioritize cracked sealants, loose flashing, and compromised membranes with compatible materials. Documenting previous repairs helps track system performance and plan targeted upgrades rather than random fixes. Coordinate with building management to align maintenance with weather patterns and avoid working in heavy rain.