The PERLOK TL FASTENER is designed to mechanically attach rigid insulation board and single-ply membrane to structural cement wood fiber, gypsum and lightweight insulating concrete roof decks. It features a high thread profile with a tapered root diameter and sharp point. Its unique design allows it to penetrate the roof deck and progressively compact the base material, creating a stronger hold in weak material. The PERLOK TL FASTENER is used in conjunction with the PERLOK 2” TL SEAM PLATE and 3” TL INSULATION PLATE.