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.
A professional concrete contractor will typically charge $2-$4 per square foot for a simple stain application, including the sealer. A stain application with patterning and sawed lines will typically cost between $4 and $10 per square foot.