Armstrong Bruce red oak strips:
Just installed, new construction, basement 65 to 75% humidity, floor joist 40 to 45% humidity. Did not see a vapor barrier installed.

What type of vapor barrier shoud have been installed?

With out a vapor barrier I understand that I will have constant problems?

What should I reccommend as a solution to the builder?

Any comments would be appreciated.

Thanks

Additional Information:

Installed on first floor, subfloor type pressed wood chip board, nail down.

Problem: Cuppping

You haven't said what your problem is, where the wood was installed (you mention basement moisture but don't specify whether the wood is below grade), the subfloor type, the installation type (floating, nail down, glue down), or the moisture readings for the subfloor or the wood.

As far as vapour barrier, not all manufacturers specify them. When our wood was installed there was no vapour barrier.

More details will be needed before the pros here can help you.

Edit: Thanks for adding the extra details.

Vapor barrier should be either

15 pound asphalt paper, rosin paper, plactic type paper, But I think the bigger problem here is your subfloor. Pressed board chip type? Particle Board?

Get a dehumidifier in the basement. Bring the rH down, in the basement, to the same level as the upper floor. Let it stay consistent for two months, and see if there is any return to a normal flat floor.

Basement floor poured AFTER the wood floor was installed perhaps? Why 75% humidity in the basement? You plan on growing marijuana down there? Just kidding. Basement's humidity way too high probably because it's new. Floor installed too soon. "chip board" is more than likely OSB, not particle board. OSB is acceptable. But your problem is the humid basement. Do as Floorguy suggests and cross your fingers.

was just going to edit my post, Just recalled people refer to OSB as chip board. =P

Basements are always higher in Relative humidity. This results in the sub-floor being high in Wood Moisture Content and that is what cupped the floor.
At this point, lowering the RH in the basement may be a band-aid that will help, not cure the problem ... is my best guess.
Where will the water drain to from the De-Humidifier?

Usually into the floor drain Ray, or just empty the container everyday.

I saw a floor cup big time because the basement slab was poured after the hardwood was installed. Even coming back later and plastering the basement walls and ceiling can cup a wood floor.