Garages are notorious for dampness. The reason: the concrete slab in a garage is NOT sealed from below. The moisture in the ground (all slabs sit on moist ground BTW) seeps up and into the garage MUCH MUCH more than in the house.

Your engineered planks are twisting because they have WAY too much moisture in them. If they are factory finished, the FINISHED side will gather moisture in a very different way than the unfinished side. And the plied middle will take moisture in a different way than the wear layer and from the bottom layer. Whew! Now how to deal with this stuff.

Bring the boxes into the house. Leave them CLOSED. Lay them flat. Do NOT stack the boxes if you can help it. They need to be laid flat. This is 'storage' only. Acclimation comes later.

Once you have brought in the HVAC people and they have turned on the heat AND THE HUMIDITY CONTROL (which you paid for because it was an added cost that you already agreed to carry because you knew you were going to have wood ... right?).

The house will take 10 days to slowly bring everything up to 'living conditions'. Once the house has been kept in the habitable range for those 10 days, you now start the 'acclimation' process. Yes. I said 'start'. We aren't even close to being done yet.

Habitable Range =

Relative Humidity (RH): between *35% - 60% (manufacturer's requirements trump 'average' living conditions) *wood prefers a 10% window to live in (like 45% - 55%) = no wild swings

Temperature Range: *55 - 85 deg F (**15 - 28 C) but the manufacturer's requirements trump 'average' living conditions *wood prefers a 10 deg. range to live in like 65 F - 75F (**18 - 23 C)

Your wood flooring professional will come in and take some random readings of the wood planks (10% is common or every 10th plank). S/he will also do the same for the subfloors. They will go away and come back a few days later (or as much as a week or two later...depending on how the first readings go). They will do the same tests once more. They will arrange to start laying the product as soon as the readings are inside the appropriate range (NWFA handbook recommendations for wood moisture content).

The highly paid flooring professional will take RH (relative humidity readings) in the house; document weather and exterior humidity each day the floor is installed. And keep track (written down) like a hammer-swinging accountant - on a spread sheet if possible - during every day it takes to install the floor.

The documents the installer creates are then handed to you - the floor's owner - so that you have documented evidence that s/he did everything by the book. The installer will keep a copy for her/his records (to prove that s/he did everything by the book).

All of this is to maintain warranty. Needless to say, NOTHING can start until the HVAC and the HUMIDITY control is up and running (properly - day and night) for 10 days.

And please make sure your well paid/trained flooring installer creates these documents. Every stick of warranty requires documentation AND strict adherence to manufacturer's requirements.