Engineered Wood Flooring- End Splits

End Splits:

Within hours to a week after edge gluing of a panel, end splits may be noted, usually, but not always, at the glue line. End splits develop only because wood is shrinking, and the only reason wood shrinks is because it’s drying. In short, end splits are caused because the panels are too wet for the dry air in the plant.

Remember that the end grain of wood dries up to 50 times faster than the edge or the face. The ends therefore dry rapidly and shrink, while the center of the panel dries and shrinks more slowly. This difference leads to stress build-up and, potentially, end splits.

To correct this problem, keep the moisture content of the lumber within 2% of the EMC of the surrounding air. Because the EMC in the plant and in the home or office is lower in the winter, lumber should be dried to a lower MC in the winter (typically 5% to 7.0% MC), and/or the plant must be humidified slightly.

Most wood flooring manufacturers allow flaws up to 5% of the installed floor; these flaws must be visible from a standing position in normal lighting.

Credit: Dr. Eugene Wengert
Professor and Extension Specialist in Wood Processing Department of Forestry, University of Wisconsin-Madison – See more at: http://www.woodweb.com/knowledge_base/Eliminating_Wood_Problems.html#sthash.mMbvVThj.dpuf