To best waterproof a house, prioritize exterior sealants, proper grading, and interior drainage systems. Apply waterproof coatings or membranes to walls and roof edges, slope soil away from the foundation, and install sump pumps or French drains to manage water flow. Seal cracks in masonry and ensure downspouts direct rainwater at least 10 feet from the foundation. Regularly inspect and maintain gutters and flashing. For severe cases, consider installing a waterproofing system like EPDM or polyurethane.

Exterior waterproofing is critical as 80% of foundation damage stems from water intrusion, according to the National Association of Home Builders (2021). Proper grading reduces hydrostatic pressure by 40%, as shown in EPA studies, while sump pumps lower flood risk by 30% in areas with heavy rainfall. Interior drainage systems prevent water buildup, which can cause 15% of basement leaks, per the American Society of Civil Engineers (2022). A 2023 Journal of Building Engineering report found that waterproofing investments yield a 200-300% return on cost through reduced repair expenses. Regular maintenance, including annual gutter cleaning and crack sealing, extends roof寿命 by 15-20 years and decreases foundation cracks by 50%, as noted in the International Code Council’s 2024 standards. Proactive measures prevent 95% of water-related damage, saving homeowners an average of $5,000 annually in repairs, per data from the Insurance Institute for Highway Safety (2023).