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.
On average most deck stains cover 150-300 sq. ft. per gallon depending on the age, condition, and porosity of the wood. To figure how much deck stain you should buy, start by measuring the deck floor. Take its width times length and write that number down. Besides the main deck floor, be sure to add in any smaller decking areas like a second tier deck or stair landing platforms.