The hvac was required before installation. As was the moisture testing of the wood and subfloor. Before installation.

It’s already messed up if you don’t own a moisture meter. And you may need to uninstall if the conditions are too humid and the floors are full of moisture. Because they will gap when dried out to normal conditions.

Sophie has beaten me to it. The heat/cooling system MUST BE on and running at "ideal living conditions". And that needs to be consistent for several DAYS BEFORE the wood is DELIVERED.

Once the wood is DELIVERED to the PERFECTLY CONDITIONED home (ahem....we are missing step 1.), then the wood acclimates to the house conditions for several days to several WEEKS (time is HIGHLY DEPENDENT on the WOOD MOISTURE readings at the time of DELIVERY....sigh).

Good, now that the home and the wood are in sync (ie. everything is at living conditions for days and days and days - or even weeks) AND the moisture readings on the wood are PERFECT, you can then install the floors.

After installation, the home must REMAIN in the "PERFECT ZONE" for ever and ever amen (pass the ketchup)! No turning off HVAC/AC while away on holidays.

As it stands RIGHT NOW....you have to turn on the HVAC and WAIT for days and days and days (or even weeks) before you can install the wood. Ooops. Too late.

So "next best option" = finish install ('cause you've already messed up and the warranty is TOTALLY void) and then WAIT. Don't do ANYTHING to these floors. Nothing. Zip. Zilch. Nada. Niente. Nix.

Cover floors with ram board and get that HVAC installed ASAP! Test the wood RIGHT NOW!!! Document what you find. Read the INSTALLATION INSTRUCTIONS and the WARRANTY instructions while you are waiting for the HVAC guys to show up!

Now you turn on HVAC and set it PRECISELY to what is needed (as per wood manufacture's requirements) and then WAIT until the WOOD reaches that point.

Good. Now FIX ALL THE PROBLEMS in the floor FIRST (and this could take a while....hopefully you have TREMENDOUS amounts of waste/overage) and THEN start your sand and finish.

I'm sorry to say but this floor could be your biggest nightmare come true. With a little luck and a SUPER HIGH END HVAC system that is many THOUSANDS OF DOLLARS MORE than the average HVAC system, you can save your wood.

Your situation is all too common. And builders need to be taken to task for allowing the installation in an unconditioned space. Please get the GC to sign a waiver stating that if this floor fails it is HIS/HER fault and he/she MUST TAKE ALL REQUIRED STEPS to remove and replace this floor to your satisfaction...and put a time limit of 5 years on that baby. Just to make sure the builder NEVER does this again!

S/He who allowed this to happen MUST BE HELD RESPONSIBLE for it! And that means a MASSIVE FINANCIAL HIT!

It’s the typical DIY failure to research properly.

You're installing an engineered product in a home without being climate controlled? Sounds to me that your warranty of the product is voided now.

Check the manufacturers website for all installation and care procedures.

Well, one thing was the wood was much different than what is available now. Much tighter grain, more dense(slower growth characteristics).The newer woods in use absorb moisture more, expand and contract more, and warp/wane more easily because the trees are grown faster.

Another, tolerances were looser for levelness from plank to plank and connection tolerances were not as stringent. Tongue and groove were less prevalent(allowing for more unimpeded movement). Many floor boards were thicker as well.

And, older flooring was installed on tight grain joists---which move less because of moisture.

Oh...and one more thing. A homeowner who built a home 100 years ago would ACCEPT a wood floor that fluctuated in size. They would ACCEPT the crowning or the cupping. It was "normal" to see these things.

And if you want proof, simply look at the wood in photos for Buckingham Palace or the OLD floors in the Hermitage in St. Petersburg (original St. Petersburg, not the one in Florida).

If you see these OLD WOOD PLANKS they are ratty. They are NASTY looking. The gaps are MASSIVE. The Queen loses a Corgi on occasion due to the HUGE gaps.

The "cure" - MASSIVE area rugs. As in rugs so large they could 1000sf at one go. That's how it 'used' to be done!

Things change. Requirements change. Expectations change. If the OP is willing to live with floors that age prematurely, gap, cup and/or crown. If they PLAN on NEVER TURNING on the heat (the inside temp = outside temp = every day of the year) then the way they have installed these floors is PERFECT.

But I doubt a new homeowner would accept or do anything like their counterpart 100 years earlier.

One of the first flooring install jobs I did was installing a plastic composite T&G click together, full floating plank product. The home owner supplied the flooring. I followed the manufacturer's installation, meaning I left a 3/8" gap around the perimeter. The smallest room was about 20' by 30' and the rest of the house was open concept with the flooring contiguous(no interruptions). Front to back section was 80+' long.

A year later, the AC failed and the inside temps went over 120°. The flooring in the small room(also full sun on about half the room) buckled in two places.

As soon as the AC was fixed and interior temps dropped back to normal, the buckled area flattened out with no perceptible damage(except where the base and shoe moldings were disturbed).

My point? Materials follow laws of physics. Heat/moisture cause expansion/swelling. Cold causes contraction. The amount of movement depends on the construction and ingredients in the product. There are all types of engineered products. Each has it's own parameters for movement/wear/etc. Example---the parquet squares that were popluar several decades ago were engineered flooring, but the construction was wood products layered into a mulitlayer product. Moisture really played havoc, since it caused the wood layers to swell differently. Kept dry, it worked quite well.

You needed the HVAC working before installation of anything wood. That means trim and cabinets too.

At this point, your only course of action is to take plenty of moisture readings and get the HVAC enabled. Then reassess in a month or so.

Engineered hardwoods are still made of 100% wood. The STRUCTURE of the planks reduces SOME of the movement in a CONTROLLED ENVIRONMENT. You do not have a controlled environment. The 100% wood planks will 100% do stuff that isn't pleasant. It will just be a snick LESS noticeable. A SNICK.

The conditions the floors were installed in is still WAAAAAAAAAY outside "happy". Which means these floors have a HUUUUUUUGE chance of being UNHAPPY - even AFTER you get the HVAC control going.

100% wood is still 100% wood is still 100% wood. It all REQUIRES the same stuff = HVAC controlled living conditions.

Temps remain STEADY: 65F - 80F

Humidity remains STEADY: 35% - 65% (please keep it inside a 10% range like 45% - 55%....PLEASE do NOT let it swing higher than that).

As you can see, the NIGHTTIME temperatures this floor has experienced are WELL outside of normal. You REALLY have to turn on the HVAC.

And PLEASE CHECK to see if you have purchased the upgraded HVAC with a built in whole home humidifier/dehumidifier. It should have been a $6K upgrade. PLEASE check!!!