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How much stain for a 12x20 deck?

A 12x20 deck floor is 240 sq ft. Deck stain covers less than wall paint (~250 sq ft/gal), so two coats need about 1.9 gallons, plus railings and stairs.

Floor, 2 coats
1.9 gallons

240 sq ft of decking.

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Frequently asked questions

How much stain for a 12x20 deck?
About 1.9 gallons for two coats of the 240 sq ft floor, plus extra for railings and steps.
How many coats of stain on a deck?
Two thin coats last longer than one thick coat; high-traffic decks may need a third.