Seasonal changes in wood floors

Reports have been coming in of cupped wood floors in the summer in Florida.  The periodic nature of this occurrence is similar to the seasonal appearance of cracks between boards in late winter and early spring in New England.  The explanation of both problems lies in the way wood reacts to changes in relative humidity and the way relative humidity reacts to changes in air temperature.  Air that is cooled 20 degrees Fahrenheit approximately doubles in relative humidity.  When warm moist air comes into contact with cool building materials the result can be either extremely high relative humidity or even water condensation on the building materials.  If these materials are the subfloor of a house with a wood floor installed on it the result can be a cupped floor.  To avoid this problem use a moisture barrier on the warm side of the floor assembly.  Insulation alone is not enough to keep the floor from high moisture unless it effectively limits the intrusion of water vapor.

Cracks between the boards in cold climates during the heating season can result from low relative humidity.  For every 20 degrees the cold outside air is warmed when it comes into the house the relative humidity halves.  This is the same process described above but in the other direction.  Over the course of several weeks of exposure to low relative humidity the wood flooring material dries out and shrinks.

Reclaimed Wood Flooring Road Trip to Key West

I went on a wood flooring road trip to beautiful Key West, Florida (about 500 miles from Micanopy, FL) to deliver reclaimed wood flooring last week. It was heart warming to reconnect with old friends.

First I wanted to see in person that a new client liked the grade of River Recovered Antique Pine we made to his custom specs. Rudy Molinet said,

“I bought my floor from your company over the other companies I talked with because your Charlotte cared more about what I wanted than just selling me a floor.”

Everyone loves Charlotte, but she is not on the web site (yet) because she is pretty camera shy. Here is Charlotte on the right, hard at work at Goodwin Heart Pine.

Heard similar sentiments as I visited with many longtime colleagues while in Key West: “Charlotte is absolutely wonderful… She always follows up… You can count on her…” When a builder said, “George is on the website, but you can’t see Charlotte”, I was reminded that she’s shy about having her photo taken. She has beautiful prematurely white hair and is quite lovely, yet you usually get her profile when taking a picture. Charlotte is in the yellow t-shirt on the right hand side of this photo of our neighbor at the Goodwin office in her clown suit. Charlotte’s not the clown… she’s the other person!

Rudy Moliet and Ales Bursa at the installation of Goodwin River Recovered Pine wood flooring.

See Rudy Molinet with his builder, Ales Bursa. You can buy Key West propery from Rudy at Marquis Property Realty. Thanks so much Rudy for loving beautiful reclaimed wood floors.

Antique Wood Flooring in Georgia

Goodwin end grain heart pine floor tiles at the Chihuly Museum in TampaCharleston One Source’s Pat Devaney met me at beautiful Glendalough Manor near Atlanta to see builder, Gary Alford last Thursday. After looking through Goodwin’s album Gary and his client chose end-grain tiles and vertical grain Antique Heart Pine wood flooring for a home they are building nearby. When we offered to pre-square and groove the pieces to help create a herringbone pattern Gary said, “Wood work is what God put me here on Earth to do.” Can’t wait to see the floors when finished.

On to my next stop…

The Yellow Bluff Company south of Savannah was lovely when I arrived late the next day at sundown to deliver a 1901 photograph of heart pine logs being rafted down river. The frame was of Goodwin’s Antique Heart Cypress to hang in the clubhouse that has Midnight Heart Pine and Legacy Vertical Antique Heart Pine flooring and stair parts.

Goodwin Midnight Heart Pine Antique Reclaimed Wood Office Furniture

I plan to visit St. Petersburg, Florida and Key West to deliver more wood flooring soon. Call if you want to come along to see beautiful antique river-recovered and reclaimed wood and meet great crafts people.

Antique Wood Flooring Myths

Download "Kiln Drying 101" by by Andrew St. James ARS PhD, COO Goodwin Heart Pine and Director of the company dry kiln.1) Some people think that antique wood does not shrink and swell anymore so it does not need to be brought to the proper moisture content on the jobsite.  On the contrary wood science and field experience both indicate antique wood shrinks or swells when the moisture content changes.  You need to install the wood at a moisture content that is close to the value that will be maintained while the building is in use.

2) We often hear the remark that old wood does not need to be kiln dried.  There are two issues here.  First, most air dried wood has a moisture content too high for interior use.  The second is the possible presence of living organisms such as powder post beetles, termites, or mold.  Kiln drying to 140 F for several hours eliminates live insect pests in the wood.  Proper kiln drying also eliminates living mold and brings the moisture content down to a level that wood will not support mold growth.  Click on the link to read more information about kiln drying in our article in WoodSource KilnDrying101 or click the thumbnail above.


Introducing Premium Mesquite

Goodwin offers Premium Mesquite… like reclaimed wood flooring it avoids cutting down the rain forest. Known for its warmth and natural beauty, Mesquite is a drought tolerant wood from regions not generally suitable forMesquite flooring other trees.  It has very good dimensional stability and is very hard wood. The wood flooring is sawn and manufactured entirely in the USA using green backers and glues with ‘no added formaldehyde’ for healthy indoor air quality. Mesquite has considerable character markings that add natural beauty. It comes in 3-1/2” or 5-1/2” widths in engineered and some wider in solid wood.

How long should you acclimate wood flooring?

We are often asked How long it takes to acclimate wood flooring?  Many people have heard of bringing wood flooring to a jobsite in advance to let it acclimate, but still do not really understand the process in detail.  The goal should be to get the moisture content of the flooring close to what it will be when the space is occupied in the long term.  Additionally the moisture content of the subfloor and the rest of the jobsite should be near to the long term value before the flooring is delivered.  The HVAC should be operating.  Installing wood flooring in a wet building is an invitation to future problems.  Moisture meters are used to measure the moisture content of wood.

The next question that commonly comes up is How do I know what the moisture content should be when the floor is installed?  The answer depends on your location and possibly some of the details of the building.  One way to learn the desired moisture content is to consult an established wood flooring professional as they should know the long term moisture content values for their geographic area.  In existing buildings you can often measure other wood that has been in place for more than a year to get a number for the appropriate moisture content.

Getting back to the original question the correct answer is not given in terms of how long but in terms of achieving the correct moisture content.

Best Reclaimed Wood Floor of the Year

Goodwin’s wood won again! DM Hardwoods created the winning entry for the National Wood Flooring Association 2010 Contest using River Recovered Antique Heart Pine from Goodwin. Here’s a photo of last year’s winner in the same category. More photos to follow as soon as they become available.