Solid hardwood · Crowning
Why is my hardwood floor crowning?
Crowning is the opposite of cupping: the center of each board is higher than the edges. It usually happens when a cupped floor was sanded flat before it dried, or when moisture reaches the top of the boards.
Also searched as: "center of the wood boards is higher than the edges", "hardwood boards are humped", "wood floor bulging in the middle"
What usually causes it
- Sanding a cupped floor before moisture levels equalized
- Moisture on the surface, such as wet mopping or spills
- Ongoing moisture imbalance between the top and bottom of the boards
What you can check yourself
- Ask whether the floor was sanded or refinished after an earlier cupping problem
- Note any wet-cleaning routines
What an independent inspection checks
- Moisture content of the flooring and the subfloor, mapped across the room
- Room temperature and relative humidity, and how they change by season
- Concrete slab moisture (ASTM F2170 in-situ RH) when the floor is over concrete
- Board profile measurements and refinishing history
Who is responsible?
Often a maintenance or refinishing timing issue rather than a product defect. The report records the evidence either way.
Get your hardwood floor inspected
Tell us what you're seeing and we'll explain the next step. We cover every county in Southern California and only inspect. We don't sell or install flooring.