I need complete, solid information on how to properly acclimate 3/4 x 3" solid hardwood Flooring, (Amendoim and Patagonian Cherry/Tiete Rosewood), after it is delivered to my home.

My home is in Sumas Washington. This is a coastal area on the west coast (Northwest corner of the United States). We have humidity here but it is in a differnt form from what most are familiar with. We call our humidity "rain". It doesn't get really get hot here. Virtually no one uses air conditioning. Some of us heat exclusivly with wood.

The daily humidity in my house over the last two years has ranged from 45% in the winter (wood Heat) to 65% in the summer. the wood moisture content of my douglas fir plywood subfloor and floor joists currently averages 10%. Humidity at floor level in the installation areas currently averages 60%.
(we do not have air conditioning, we just leave the windows open at night to cool the house down if it gets above 70 degrees inside). Crawl space is fully insulated. 6mill Polyethylene vapor barrier on the ground seams overlaped 4 feet and double taped then run up the foundation walls and glue sealed. 2" double foil faced Polyisocaranate on the concrete foundation walls seams sealed with expanding foam. Ground vapor barrier on ground then covered with 1" double plastic film faced Styrofoam insulation board with all seams taped. That is then covered by an additional 6 mill Black Polyethylene vapor barrier seams overlapped by 6 feet and double tape sealed, also continuous tape sealed to first poly vapor barrier on foundation wall. Crawl space humidity is continuously monitored with wireless remote humidity gauge sending unit and it's air is exchanged if humidity rises above normal range.

So far the advice I have received has ranged from "Just stack the unopened boxes up in the room where it is to be installed for a few days" to "Remove the wood from the boxes and sticker stack it, then circulate air through it with fans till it reaches EMC (Equilibrium Moisture Content) consistent with your carefully monitored and controlled average Realative Humidity."

I really need thorough, accurate and complete instructions on how to acclimate the wood when it arrives so that I don't make any mistakes.

Thanks Much,

Wylin

When I visited Hearst Castle in San Simeon, CA., one of the things the guide showed us was how carefully they controlled the humidity INSIDE the castle. The reason? There are invaluable pieces of furniture, artwork, and the like. Hearst Castle does not have AC either and is very near the Pacific Ocean. What they had was small humidistats in many various areas that monitored the humidity and temperature. They said their ideal was 50% RH. They opened and closed doors and windows to control humidity levels. In the winter, the furnaces also controlled RH as well as temp.

What does this mean to you? You'll have to do similar. Monitor RH and adjust as you can. In your case, due to your rainy area, 50% RH would seem to be your medium. In the winter, you may need to add humidity unless you can live with some gaps between the boards.

So, first is to have your home's interior as close to normal and ideal at 50% RH and make every effort to maintain that. Bring in the flooring and take a moisture meter reading right away. 8% MC overall would be good. Too high of MC and you'll get gaps as the wood dries. Too low and it will expand, causing a slight cupped appearance. Moisture test the subfloor. It should be no greater than 10%. IF you could moisture test every board and they all read 8%, I'd say start installing. But that rarely is the case. Usually, the wood comes in varying MC, like 7 to 9%. So that's why it is sometimes recommended to let it sit in the home for awhile. How long depends on the MC of the wood and the MC of the subfloor and the RH of the environment. Removing it from the cartons and stickering it will reduce the amount of time it takes to "acclimate" but may not be needed. Call the tech. dept. of the manufacturer and get their recommendations in writing. That's a good place to start.

I agree with Gary on contacting the manufacturer. Most manu's say between 35-55% or 40-60% RH, it just depends on the manufacturer. Contact them and specifically tell them the area of the country you live in. Also explain that you don't run the AC they will probably take the safe side and say that if you don't run AC they won't warranty the product but do check and see what they say....and get it in writing!

Acclimation is a moisture thing, not a time thing.

With that said, right now it is 26%rh @86ºf

My regional map for moisture content says, Sumas Washington area is 9-10% MC