MOISTURE IN WOOD

One of the most important items to deal with when installing hardwood floors is moisture content.  The atmospheric conditions of the room, the moisture content of the subfloor as well as the moisture content of the hardwood are all critical to a successful and long lasting installation.  Every day we receive phone calls pertaining to moisture and how to check for and resolve the problems of moisture.  Below are a few tips on dealing with what could be a costly unseen menace.

When installing hardwood in a newly constructed home, the house should be as close to the normal living conditions as possible (i.e. windows and doors installed and closed, temperature regulated).
Using a moisture meter, check the moisture content of both the subfloor and the hardwood to be installed.  A level of 6% to 9% is normal. Be sure to record the level for later reference.  If necessary, stabilize the moisture conditions in the home by closing doors and windows. The hardwood should be removed from its packaging and spread out evenly in the room, 3-4 days if possible to acclimate.
Once all this has been done, check the moisture levels again of the hardwood and subfloor. The subfloor should be NO MORE THAN 4 PERCENTAGE POINTS ABOVE OR BELOW the hardwood.
If you're in the business of selling and installing hardwood, having a moisture meter is critical.  There are two kinds of moisture meters, Probe and Pinless. The probe type has opposed sets of pins that are pushed into the wood to obtain a reading and has the advantage of measuring moisture at varying depths. The pinless type can be moved across the surface to identify moisture pockets.
I can't stress enough how critical it is to check the moisture before you install hardwood. Remember, a little prevention can save you a bundle!!

CUPPING AND CROWNING

CUPPING is when the edges of the board are high and its center is lower.  It occurs when the bottom of the wood flooring remains wetter than the top surface.  It can occur after water is spilled and is absorbed through the wood.  The first step to curing cupping is to find the source of the problem.  It may be a leaking ice machine, or dishwasher or any number of sources.  Whatever the source, once you take care of the problem the floor may improve on its own. Using fans will help dry the wood.

CROWNING  is the opposite of cupping.  The center of the board is higher than the edges.  It can occur from exposure to excessive moisture on the surface but more commonly comes from trying to repair a CUPPED surface by sanding it down before the moisture below had been removed.  Eventually, the bottom of the boards dry and flatten out leaving the once evenly sanded surfaces crowned.