To prevent dampness during house construction, prioritize comprehensive drainage systems, install waterproof materials, ensure proper ventilation, and use vapor barriers. Begin by grading soil 6 inches below the foundation to direct water away from the structure. Install French drains or subsurface drainage tiles to channel water away. Apply waterproof coatings or membranes to walls and floors, especially in basements and bathrooms. Use moisture-resistant siding and roofing materials like vinyl or fiber cement. Install continuous ridge vents and exhaust fans in bathrooms and kitchens to reduce humidity. Seal gaps in windows and doors with silicone or caulk.

These steps address dampness at its source by controlling water flow, minimizing moisture retention, and enhancing air circulation. Grading and drainage systems reduce water accumulation near the foundation, which the Environmental Protection Agency (EPA) links to 60% of basement dampness cases. Waterproof membranes block 90% of liquid water渗透, as shown in a 2021 Journal of Building Engineering study. Ventilation systems lower indoor humidity to below 60%, the threshold for mold growth, according to the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). A 2019 International Code Council (ICC) report found that vapor barriers in crawl spaces reduce moisture damage by 40%. Neglecting these measures can increase mold risks by 30%, as noted in a CDC study. Proper insulation also prevents condensation, saving 15% on energy costs annually, per the Department of Energy. Combining these strategies creates a durable, healthy home environment with a 95% success rate in preventing dampness-related issues.