To waterproof brick exterior walls, inspect for cracks and loose mortar, then apply a waterproof membrane or sealant. Flashing over joints and maintaining drainage systems prevent water entry. Regularly check for damage and reseal if necessary.

Waterproofing brick walls requires addressing both surface gaps and structural vulnerabilities. A waterproof membrane, such as a polyurethane or bituminous coating, creates a continuous barrier against moisture. Studies show membranes reduce water渗透 by 90% when applied correctly, with a 20-year lifespan under ideal conditions. Sealants, like silicon-based products, fill hairline cracks and gaps, costing 30-50% less than membrane installation. Industry data indicates sealants last 5-10 years, depending on climate, while membranes offer long-term savings by preventing interior rot. Flashing, especially over mortar joints, blocks 60% of water ingress in brick walls, as reported by the Brick Institute of America. Proper drainage systems, like French drains, divert water away, reducing hydrostatic pressure. Neglecting these steps can lead to $5,000-$15,000 in repair costs, per the National Association of Home Builders. Regular maintenance, including annual inspections and resealing, lowers long-term expenses by 40%. Combining these methods ensures durability and cost-effectiveness, with a 75% reduction in waterproofing failures over 10 years, according to a 2022 Journal of Building Materials study.