Gebr. Sleeuwenhoek, founded by Aart and Kees Sleeuwenhoek, has been operating as a demolition contractor and trader in recovered materials since 1971. Today, three generations later, the family business still specialises in the dismantling and sale of old building materials. The company's main focus is old roof tiles (with a large selection of typical old Dutch roof tiles in particular). In addition to roof tiles, they also sell find bricks, wooden beams, doors, ironwork and ceramic tiles. Gebroeders Sleeuwenhoek’s regular customers include both private individuals and contractors.