When making a loan and the property is in a flood zone would the 30-day waiting period apply if the premium was not paid until after the closing date?

Yes and that would also cause a violation for not having an effective flood policy in place at or before closing.

(b) Where the initial purchase of flood insurance is in connection with the making, increasing, extension, or renewal of a loan, the coverage with respect to the property which is the subject of the loan shall be effective as of the time of the loan closing, provided the written request for the coverage is received by the NFIP and the flood insurance policy is applied for and the presentment of payment of premium is made at or prior to the loan closing.

Thanks Dan.