Butyl tape is an example of a synthetic rubber adhesive. It’s a solvent-based adhesive that is formulated in the lab instead of coming from a rubber tree. All types of rubber adhesive are thermoplastic, so exposure to high heat will soften the adhesive and impact its effectiveness. However, butyl adhesives are formulated to be less sensitive to temperature variations. They stay more flexible in cold weather and more stable in high temperatures than natural rubber adhesives. Because butyl tapes are extremely durable,  with have good flex properties, they are often used in applications where an airtight bond is required. In fact, most butyl tapes also come with a liner since the adhesive system is aggressive and forms a permanent bond to the surface it sticks to – even if that surface is itself!


Advantages:


  • High initial tack­—has a more aggressive hold on contact than acrylic adhesives
  • Has a high level of adhesion because it bonds to a huge variety of surfaces
  • Less expensive than acrylic adhesive
  • Impermeable to air
  • Waterproof so it works well in situations where water is a factor

Disadvantages:


  • Even though butyl adhesives are less sensitive to temperature variations they still cannot match the range or performance of acrylic adhesives.
  • Does not hold up over time to direct exposure to UV light or chemicals
  • Susceptible to oxidation and may darken or discolor

Ideal for:


  • Seaming and flashing windows and doors
  • Repairing leaks