Xpanda 600 Joint Sealing Tape Is A Soft And Flexible Expanding Foam Used Primarily As A Weather Seal To Prevent Water Infiltration And Retain Heat In External And Internal Applications. Along With Its Excellent Acoustic Properties, It Will Produce A Weatherproof 600 Pascal Rating Under High Compression. In Low Compression Applications It Provides A Tensile, Aesthetically Pleasing Bond Between Smooth Or Irregular Surfaces Such As Masonry, Concrete, Wood And Plastics Etc. The Foam Is An Open Cell Polyurethane, Heavily Impregnated With Uv And Water Repellent Acrylic Based Resins Which Are Also Heavy Are Flammable. It Comes In Pre Compressed, Slow Stretch Rolls With A Self Adhesive Grid Tape On One Side For Ease Of Application.