In most cases, yes. While most manufacturers apply a sealant to their cork tiles or planks before the product leaves the factory, this protective layer doesn’t last long. Always use another layer or two of polyurethane or similar sealant after installation. This step ensures that no moisture penetrates the cork, and damages the floor or gives rise to mould. After the first application of sealant apply a new layer every 2 to 3 years.