What is the desired relative humidity in a crawl space?

In a crawl space, what is the desired relative humidity? If mold were the only consideration, what is the maximum relative humidity that you should allow to insure that mold won't grow? Are there other considerations than mold? Any help will be appreciated.
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You need to keep it below the dew point.

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Ok Why would you want the humidity to be below the dew point?
want it to rain in the crawl...

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snipped-for-privacy@NOSPAMjuno.com wrote:

Generally I would say below 60% and not likely lower than 40%. What is important is that it not approach near 100%
--
Joseph Meehan

Dia duit
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http://www.buildingscience.com/resources/moisture/relative_humidity_0402.pdf
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