• Synthetics does not support mold growth
• High durability and weathering capabilities  
• Self-sealing compound ensures nail sealing
• High temperature resistance (Up to 225°F)
• Bitumen seam locks at the edges for total watertightness
• Enhanced adhesion with new Super-tack compounding technology
• Polypropylene mat surface has good anti-slip properties with high walkability features: Makes it highly suitable for application on sloped roofs.

iStik SU40 is a premium-grade self-adhering underlayment based on the peel-and-stick technology. The underlayment is used as a secondary barrier against water and moisture under asphalt shingles, metal profiles, slate, and tiles. iStik SU40 is a composite membrane which is designed and manufactured to meet the industry standards. A polymer-modified bitumen compound is laminated onto a non-woven polypropylene fabric. Selected grades of polymers are used to enhance the adhesion of the underlayment on plywood, OSBs, wooden particle boards, concrete, and metal surfaces. The tough Polypropylene mat has excellent anti-slip properties for improving walkability on sloped roofs. The adhesive compound and the tough surface together act to provide excellent temperature resistance and high durability against weathering.