Redwood deck in Colorado: to space or not to space?

[HighOnTCP]

The choice is definitely redwood (already purchased), and while the deck (in my opinion) will look nicer with no spacing between the planks, I don't want to risk damaging them from shrinking and expanding in the Colorado weather. I have heard just as many "no reason to space, redwood shrinks/expands very little" as I have "definitely space, you will have problems if you don't" answers to the question.

So is there anyone that lives in Colorado or a similar climate that has experienced this specifically and can give some "been there, done that" advice?

thanks, Erik

[Don Phillipson]

Colorado weather probably offers greater extremes of high and low humidity than places farther west or south.

Expansion/contraction of deck timbers is less important than drainage. After rain, any wood deck should let the water run off as fast as possible, i.e. through the quarter- inch gaps left between timbers. Secondly a deck of spaced timbers is easier to clean, sweeping so that dry dust falls between timbers. If you built a flush deck it would become stained and/or rotten much faster than a correctly-spaced one.