Water Absorption – Technical Explanation

Water absorption is a critical performance index that directly reflects the water resistance, dimensional stability, and service life of floor underlayment materials.

Our magnesium oxide underlayment floor board is manufactured with a chloride‑free magnesium sulfate formulation, which features stable internal structure and low hygroscopicity.Standard water absorption: ≤ 15%

Under high humidity or short‑term water immersion, the board does not swell, warp, soften, or delaminate. It maintains excellent dimensional stability and structural integrity, avoiding common problems such as floor squeaking, hollowing, lifting, or cracking caused by material expansion.

Being inorganic and non‑cellulosic, the board does not provide nutrients for mold, mildew, or termites. It remains stable and durable in wet areas including basements, kitchens, bathrooms, and ground floors.

Compared with plywood, OSB, and gypsum board, MGO underlayment has much lower water absorption and significantly better performance in humid environments, making it a high‑reliability substrate for premium flooring systems.