By the early 1990s, Rwanda, a small country with an overwhelmingly agricultural economy, had one of the highest population densities in Africa. About 85 percent of its population is Hutu; the rest is Tutsi, along with a small number of Twa, a Pygmy group who were the original inhabitants of Rwanda.
1 Power sanding, stain and seal â This is a very aggressive procedure normally used on decks that have not been well kept or are changing color. The average cost is $2 to $4 per square foot.  Light sanding, stain and seal â This is a general annual treatment for a deck.
1 For sealing alone on a 250 square foot deck, expect to pay $300 to $400. 2  Staining a deck of the same size might cost $400 to $600. 3  Again, expect costs to rise for larger decks. 4  A gallon of deck stain or sealant costs $25 to $40. For sealing alone on a 250 square foot deck, expect to pay $300 to $400. 2  Staining a deck of the same size might cost $400 to $600. 3  Again, expect costs to rise for larger decks. 4  A gallon of deck stain or sealant costs $25 to $40.