Teak Floor laying question

I have just built an enclosed porch. The subfloors are 3/4" ply. The floor is going to be 3" x 3/4" tongue and groove teak. It should not get wet, but will have some temp variations. (winter heating is optional)
Should I use an underlayment?
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What's under the subfloor?? If it does not have a vapor barrier of some kind, I would put an underlayment over the ply
John

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The floor is (from ground up) 1/2 ply, 2x8s on 16" centers, and then the 3/4" subfloor, sitting on cement footings. There is unsulation with vapor barrier between all the 2x8s
wrote:

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