Alder Stair Tread – 98448 Call For Quote $64.69 Interior Tread 1″ x 11-1/2″ View Product Catalog Alder Stair Tread - 98448 quantity Add to list Want a discount? Become a member. SKU: a98448 Category: Stair Parts Description Description A98448 – Alder tread for interior stair systems. 1″ thick x 11-1/2″ from nose to back. Available in 48″, other sizes available by special order