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.
For the purpose of this discussion we will review the costs and materials required to stain (and clean) a deck measuring roughly 20'x25' (or 500 square feet) on a DIY basis. According to AskTheHandyman.net the average professional is going to require between three and five hours to tackle the work, with costs averaging at roughly $2 per square foot.