WidgetCo® 12mm (1/2") Cork Underlayment Sheets are among the oldest and most respected brand of cork underlayment in the USA and made from natural, European cork.. Cork Underlayment Sheets is a natural sound insulator and will work with both wood floors and tiles to help reduce walking noise and act as a thermal insulator. Also ideal for to cork table top for a work area! Cork natural properties resist mold and mildew. Each sheet is 6 sq. ft. (12mm x 2' x 3'). Each box contains 8 sheets or 48 sq. ft. 12mm (1/2") Cork Underlayment Sheets install quickly and easily and do not curl up as can occur on underlayment rolls. Bulk available.