What causes cupping?
A floor that is cupping (raised edges across the width of a board) has experienced some water damage or humid condition. The board/boards have experienced an increase in moisture content and have actually “grown” in width. When there isn’t enough space to expand the boards will curl up. Common causes can be: airborne humidity; wet basement or crawl space; lot topography; rain handling provisions; leaks in plumbing; capillary actions through slab; door leaks. To fix the problem the floor must be dried out thoroughly with heat, airflow, and dehumidifiers. Allow time. It often will lie back down. Most cupped floors do not need to be replaced. Many are salvageable. If the floor needs to be corrected immediately, then replacing may be the only solution. If the floor lies back down then a simple refinish may be necessary.
