The Best Value In Premium Sub-Flooring

Now With Proven Protection Against Termites and Fungal Decay

LP® TopNotch® 350 ZB Premium OSB Sub-Flooring Treated With Zinc Borate delivers strength, stiffness and premium moisture resistance as well as zinc borate protection at a great price. LP TopNotch 350 ZB creates a strong, smooth surface ready for your finished flooring application. The self-spacing tongue-and-groove profile speeds installation with no special tools or handling. Our zinc borate protection provides lasting defense against termites and fungal decay. Backed with a 100-Day "No Sand" Warranty and a 25-Year Limited Warranty.