Laminate flooring is a hygroscopic material, meaning its core—usually HDF or MDF—responds to environmental moisture levels. When humidity is consistently high, the core fibers absorb ambient moisture and expand. If the expansion gaps at the walls are insufficient or if the planks are sealed tight, this expansion forces the edges to rise (peaking) or the center to lift (cupping). Maintaining humidity between 35% and 55% is generally recommended to prevent these dimensional stability issues.
Ask an ExpertLaminate
Can excessive humidity cause laminate planks to cup or peak?
Yes, excessive humidity can cause laminate planks to cup or peak. Because laminate cores are typically made of high-density fiberboard, they absorb moisture from the air, causing the planks to expand. This pressure leads to lifted edges or bowed centers if the subfloor is not dry.