rmverb, I'm not a professional but this happened to my sister in law when she had new floors installed after a leak in her house. There were swirl marks everywhere from the buffer. They're hard to see until the finish goes on. Unfortunately I think the only way to get rid of them is to sand the floors down to bare wood then buff the swirls out and stain/poly again.

http://www.hardwoodfloorsmag.com/sanding-finishing/beware-the-swirls-take-your-buffer-technique-to-the-next-level.html

If these swirls are everywhere and can be seen at standing height in normal lighting conditions, then it is unacceptable.

Sanding marks...not considered an acceptable finish (under the circumstances listed by glennsfc). These floors can and should be sanded and refinished.

It looks like this is underneath the finish - in the stain. I can't be sure from one picture...but if this is at the "stain" level, this is not from buffing. This is from the last pass with the sander before stain was applied. That means you have to sand everything down, get past the stain and do that "last" pass again.

Don't let them continue. Please bring the GC and the floor finisher back on site so that you can point out what has happened and that you are are looking for resolution on the issue.

And to be clear, because of this the flooring professionals have reduced the life span of your hardwood by 20 years (or so). Every time you stand and refinish, you take off 20 years of service. Considering that a hardwood floor has 3-4 sand/refinishes in them, they have a life span of 60-100 years (60-80 years is very common).

A mistake like this can cost your floor one set of "20 years". You may not get compensation for that...but you want to point out that you are not happy with this turn of events and what it has done to the floor's longevity.

I sent this photo to my builder. Haven't received a response yet.

Proper machine use is achieved by years of practice and the right machinery for the job. The "Trio-type" machine, or a buffer accessory equivalent, is the only way to go to assure a swirl-free result when preparing for stain. That said, I am sure there are guys and gals who use a rotary buffer to prepare a floor surface and get excellent results.

These swirls are everywhere, not just one area. Meeting with the builder today onsite so we'll see what he says. My gut feeling tells me he's going to minimize the issue and say that swirls are to be expected.

If he states that, tell him before you pay you will a NWFA Inspector out at your cost to inspect. And if the inspector says it is to be expected you will cut him a check on the spot.

We met with the builder today at the house and he had the owner of the hardwood company come. The hardwood guy was not happy with what he saw. He wasn't onsite when the job was done. We don't know the extent of the issue since half of the floors are covered with paper. They are going to rip up the paper tomorrow and inspect every inch of the floor. The hardwood guy mentioned only doing re-doing certain areas but I don't know how I feel about that.

They pulled the paper up in the kitchen and great room and found more of the same swirls. They are going to sand and re-finish the whole first floor.

Since this is a brand new floor what did they say about the fact that they have taken one refinishing and 20 years or so off the life of your floor?

I brought it up to the owner of the company and he said that since they are only taking the finish off they aren't removing that much material.

I agree with that take. The floor is already sanded flat so refinishing at this point doesn't remove much wood.

Someone here made the claim that screening is an outdated technique. We generally screen the floor once after the Trio. What is the consensus on that?

TIA

Fair enough.

Dishing's caused more by too much tension on the drum/belt sander and/or walking too slowly. Screening a properly sanded floor with 100 or 120 will not cause dishout. The amount of pressure applied by the buffer isn't sufficient to cause it and the grit of abrasive isn't that aggressive.

It's pretty widely accepted that most dishout is caused by the big machine.
After you Trio the floor, there isn't enough screening done to cause dishout and as I pointed out, the weight of the buffer divided by the area sanded doesn't provide enough pressure to cause dishout with a 100 or 120 grit screen. I seriously doubt I could cause dishout even if I tried. I also haven't experienced the release of grit on the floor as you claim but I'm mainly buffing with using dust pickup. Perhaps if one was not using the Trio and was buffing with a heavier grit sandpaper for a longer period of time to eliminate ripples or chatter, I could see it, but in that case one should be using a hardplate. Even then the screening process after the hardplate isn't aggressive or extensive enough to cause dishout.
Perhaps you're using the term "screening" to refer to the entire process done after the edging and big machine work. If so, I can see your point.

http://www.hardwoodfloorsmag.com/component/com_kunena/Itemid,292/catid,6/id,404/view,topic/

Id add, screen the next refinish crew

Some people claim that the Trio can leave little squiggly marks. I have never seen that. I don't screen after the Trio, but I assume it would be done to open the grain some to accept more stain pigment? Or...is it as a final pass to remove squigglys?