Just had my floors installed and finished. The flooring is three-quarter by 3 1/4 rift and quartered red Oak. The problem with the floors is they rough and feel like sandpaper under your feet . I have the installer come back and apply another coat of poly it helped a little but the was still have a bumpy look to them . Can anyone advise me what went wrong and what I should tell the contractor to do to fix this problem .
Dana

Any combination of things. One would be airborne dust during the curing time. Not enough finish applied. Bad (contaminated) finish etc.

But feels like sandpaper?

Saying they were finished and are rough is too vague without a picture. I could guess at a few things.

If they were finished with water based finish, the moisture probably raised the grain and would be prominent depending on how the finisher prepped the floor between coats.

If you stained the floor and they water popped the floor, that could also cause grain raise, and again...if they didn't prep the floor between coats properly, could end up with rough/bumpiness.

The other possibility, which we've been experiencing randomly due to the high level of humidity we've been having in MN, is light alligatoring of the wood in the soft grain with oil based finish. It looks like grains of sand in the darker grain of the wood. It won't always go away with an extra coat of finish as the moisture in the wood needs to dry out enough to not try to push up through the new coat of finish. A moisture meter would be helpful in determining if that were the cause.

Beyond that, bumps could be caused by improper cleaning of the floor prior to the coat, but I'd be willing to bet more that it's one of the scenarios I described above.