Which of the following is a primary characteristic of pressure-sensitive adhesive?

A primary characteristic of pressure-sensitive adhesive is its ability to be repositioned after placement. This property allows installers to adjust the positioning of flooring materials, such as carpet or vinyl, without damaging the substrate or the adhesive itself.

Pressure-sensitive adhesives remain tacky at room temperature, which provides the flexibility to lift and reposition flooring products until they are firmly set. This characteristic is particularly advantageous in floor covering applications where precision placement is critical, allowing for adjustments to achieve perfect alignment without having to apply heat or wait for the adhesive to cure.

The other characteristics listed do not align with the unique properties of pressure-sensitive adhesives. For instance, requiring heat to activate describes heat-activated adhesives, while drying quickly pertains more to other types of adhesives that bond through evaporation or curing. Waterproofing is not inherently a characteristic of pressure-sensitive adhesives; it depends on the specific formulation of the adhesive rather than the type itself. Thus, the ability to be repositioned is what distinguishes pressure-sensitive adhesives in the context of flooring installations.