Dexerdry strips are specially designed to weatherproof outside decks. This system of gutter flanges fit between grooved deck boards to create dry space under your deck. Dexerdry strips are not make from rubber, they are made of a proprietary blend of thermoplastic, designed to withstand rain, sun and elements.
See instructions in the link below to learn more about weatherproofing your under-deck space.
Cost effective solution for creating dry space under your deck
Eliminates debris falling between boards onto the joists