These floating floors need about a half inch around the perimeter of the room to allow for expansion. Typically the baseboard is installed over the top of the floor after the flooring is installed to hide the expansion strip.

I've put down two floating floors, pergo and wood and the baseboard gets installed at the end to hide the expansion strip.

Thanks to both of you ... confirming what I was thinking.

Don't put in the baseboards first!!! That's how it was done originally in our home and now that we're renovating it's a major PITA to try to get them out without wrecking the flooring. We have to carefully and tediously slice them with a Fyn tool. Ugh.

That is why it should take more than $150 and a weekend of your time to become a GC! Not to offend GCs. I'm one too, but seriously...my grandma could become one if she wanted too...seriously

Well I have no problem with my GC, who has been in the business for, well, a lot longer than I've been alive probably.

I talked to him about it again and he's just sensitive about the floors because we've been busting their butts about being nice to the floors throughout this whole project and I think he was hoping to finish everything but the shoe molding in the bedrooms so he wouldn't be walking on the floors at all. I'm not worried about it. They seem to be tough as nails and we'll cover them a bit when we're done.

Anyway, thanks all!

It's better to do the floor first, but some installers leave existing baseboards and add a quarter-round moulding to hide the expansion gap.

This is why I'm installing my floating floor myself.

In new construction it is normal for the baseboards to go on before the floor goes in, I think mostly because that is simply the order in which it is done. The floors are usually last.

It you don't want gaps between the baseboard and the floor, put the floor in first.

Followup: I should add that my reason for putting in the bb first is to minimize damage to the finished floors from the trim carpenters working on top of them.

"The baseboard will cover gap, but the floor will still expand and contract imperceptibly with temperature changes."

It is not temperature changes but humidity changes that make wood floors expand and contract.

A floating floor acts as a single large piece of wood, and the movement can be rather large, even with cross grain construction.

A strip hardwood floor has only one edge of each strip fastened, and the other edge is free to move with humidity.
This is why the gaps between strips are normally larger during heating season (low humidity) and close up nearly completely during cooling season (high humidity).

Each board moves a small fraction of an inch, so the movement is spread over the entire floor.

Boards do not appreciably change length, just width and thickness.

It would only be damage if you plan to nail it on the floor.

I was referring to the unintentional scratches, scrapes and dings incurred when trades are walking, dragging equipment and dropping things on top of new wood floors.

I have been in the engineering and construction arena since 1964 and the best option depends on the type of baseboard. But generally the baseboard goes in place first and then 2nd the floor whether ceramic or vinyl tile, hardwood or laminate and the shoe mold 3rd (most times no shoe molding when installing carpet). The shoe mold will cover any expansion gaps against the baseboard. Look at it this way flooring and underlayment comes in various thicknesses and if you ever need or want to change the flooring (thinner or thicker than the existing flooring) most likely if the baseboard is installed on top of the original floor it will need to be removed to fit the new flooring style. AND if the new flooring is thinner it may require not only removal of the baseboard (to lower it) and repair the wall and paint (or wallpaper) the difference. In other words why limit your options, baseboard first. Just removing and reinstalling or replacing the shoe mold to install a new floor is much, much more easier and less expensive. Besides you want low resistance on the floor for expansion and contraction and placing the baseboard on top of the flooring adds resistance (shoe mold is nailed to the baseboard not through the flooring). NOTE: This recommendation is for dry locations like bedrooms, dining rooms, living rooms, family rooms. Wet locations like bathrooms, laundry/wash rooms, mud rooms, kitchens etc. is a different application.