Cabot Australian Timber Oil is the perfect unique blend of oils for the protection of dense tallowwood, cambara, and merbau from high exposures. It can be used for Decks, Outdoor Furniture, Railings, and Siding. As for coverage, the spread rate varies depending on the surface's porosity. On smoother surfaces, 3400 series covers about 400-600 square feet per gallon and 19400 series covers about 250-350 sqaure feet per gallon.