Yes, you should be worried. Your floor needs to acclimate. And you don't use a "subfloor" under wood flooring over concrete. You use a troweled on applied moisture barrier and then an appropriate urethane glue to glue down engineered wood.

You aren't going to make your deadline. And you may need to switch installers.

Argh--thought I had cause to be concerned. Yikes. I'm frustrated because this guy had a ton of great reviews on Angie's List and seemed really knowledable at the initial meeting. He initially mentioned that the wood would need to acclimate about 3 days, which was comparable to what we heard from a couple of other installers. Two of the other installers told us 5-7 days to acclimate the wood.

I'm not sure if subfloor is the right word. I do think something was troweled on the cement after the existing was taken up but then sheets of plywood were put down. The actually wood flooring hasn't been installed yet (since it just got to the house today). It's not engineered, just plain unfinished select oak boards which will be stained and sealed.

So I guess I really need to revise our schedule and moving plans, right? I feel my stress level rising as I type!

You need to give the floor person the proper amount of time to do the job.
It sounds like he's a day behind on what was already an impossible schedule.
I would suggest you tell your floor guy that you're putting off the move until he's done with the floor and ask him, without pressure, exactly how much time he needs to do the job right and to warrant the finished product.
Some contractors will take shortcuts just to please a customer without regard to the negative effects.
I can't speak to how long your wood should be acclimated since I may live where the climate is different, but we allow 2 WEEKS to pass between the time we lay the floor and start sanding. In instances where we are asked to shortcut the recommended acclimation process, I advise my customers of what the pitfalls might be and if necessary, relieve myself of the liability if something goes wrong.
To put your stress in perspective, consider the inconvenience you'll go through if the floor job is rushed, then goes bad, either right away or after you've moved in.

And disregard the comment above about subfloors. It is acceptable to fasten a layer of 3/4" plywood over concrete to allow for nail-down installation of solid wood flooring. There's even instructions on how to do it in the NWFA and old NOFMA manuals.

With a little 'luck' you may get in on Friday and your floor may be just fine. Two people may be able to install stain and finish your oak in time for you move in...but be aware that the finish will only be partially cured and will add a smell to the rooms as it cures.

This situation sounds like a 'shot in the dark' to me and it is what many installers face with fast-track new home construction.

Good luck.

With a little 'luck' you may get in on Friday and your floor may be just fine. Two people may be able to install stain and finish your oak in time for you move in...but be aware that the finish will only be partially cured and will add a smell to the rooms as it cures.

This situation sounds like a 'shot in the dark' to me and it is what many installers face with fast-track new home construction.

Good luck.

I've seen what lurks under plywood on top of concrete. Mold and mildew and delaminating plywood. And then the wood on top still cups from too much moisture being transmitted through it. I only recommend engineered flooring on top of slab foundations. It's a much safer bet for long term happiness.

And yes, the wood needs to be acclimated. Opening the boxes and stacking the layers with spaces between them and alternating the direction of each layer will speed that up rather than leaving it in it's boxes. Like a Jenga tower.

And for the record. You Never acclimate engineered wood flooring. Unless the manufactor specifically states to do so b

Most of the time engineer flooring is made up of different species of wood. I.e
If you have oak engineered wood. It would be an oak layer then a cheaper wood like pine and then the last layer would be oak or another species.

You dont acclimate engineered because those different species absorb moisture at different rates.

You ever wonder why inside each bundle of engineered flooring its completely shrink wrapped?

Thanks for the info, everyone. I really appreciate it.

We adjusted the schedule as much as we could to allow for an extra day to move in. It's not much, but better than nothing, I suppose.

When we visted the house yesterday, the flooring was laid out in the rooms. Installation should start soon. There's a team of people working on the flooring so I'm not worried about the actual work being done, but more than the wood might not be fully acclimated when installed.

It's not a new construction house, just new to us. :-) My husband tried to talk me into engineered wood on the ground floor, but I insisted on "real" wood. Sigh. Am having second thoughts about that now but too late. Oh well--will cross my fingers and hope for the best.

My installer doesn't think that the wood moisture levels will be an issue so I'm just going to trust him. The floors being refinished on the second floor look amazing so I'm hoping for a similar end result.

Thanks again everyone for taking the time to respond!.