New Image Coatings of Manchester, NH has developed a waterproofer that is NHDES approved to be applied to the decking near water. SEAL-ONCE waterproofers for wood, concrete, masonry and composite decking provide long-lasting protection against water and UV damage. They’re Eco-friendly, water-base, non-flammable and contain zero VOCs, toxins or irritants. They are available in clear or tinted colors. Be sure to stop by the store and have our staff show you SEAL-ONCE.