1. people whose job is to make buildings, structures, or materials resistant to water penetration
2. substances or products used to make materials waterproof

Examples

• The waterproofers arrived early to seal the basement walls.
• Professional waterproofers use specialized equipment to protect foundations.
• We hired experienced waterproofers to fix the leaking roof.
• The hardware store sells various waterproofers for outdoor fabrics.
• These waterproofers will keep your boots dry in wet conditions.
• The waterproofers recommended a membrane system for the deck.