Why this "selfie" needs pressure

Self-adhering sheet applied products are popular options for many construction products including waterproofing, roofing underlayments and Air & Vapor Barriers. The majority of sheet applied membranes are comprised of pressure sensitive rubberized asphalt and HDPE (High Density Polyethylene) or HDPP (High Density Polypropylene). The rubberized asphalt/adhesive compounds are pressure sensitive, meaning pressure should be applied to obtain proper adhesion. Pressure is typically applied by hand rubbing, hand rolling, weighted rollers or by broom.

As a manufacturer of self-adhering sheet applied products, our best practices always include instructions to apply pressure once the membrane is installed. But it begs the question: if the product is self-adhering, why go the extra mile? The number one reason is that the additional pressure multiplies adhesion strength 400 times. Done correctly, that membrane will adhere to the substrate throughout the intended life of the product! Other reasons include:
•    Tested and proven methods ensure warranty requirements
•    Good construction practices reflect positively on you and instill confidence from owner

Athletes talk about peak performance under pressure. The same holds true for self-adhering sheet applied membranes.  To get peak performance, apply pressure.