Expansion gaps are essential for the structural integrity of hardwood floors. Because wood is a natural, hygroscopic material, it constantly gains and loses moisture from its environment, leading to physical swelling or shrinking. If installed flush against a wall without a gap, these seasonal movements can cause the floor to buckle, tent, or crack. Manufacturers typically specify a gap equal to the thickness of the flooring board, which is then concealed by baseboards or quarter-round molding.
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What are expansion gaps and why are they necessary?
Expansion gaps are deliberate spaces left between the hardwood flooring and walls or vertical obstructions. They are necessary to accommodate the natural hygroscopic expansion and contraction of wood as indoor humidity and temperature levels fluctuate throughout the year.