What is used to ensure tight seams when applying hot-melt adhesive?

A seam roller is an essential tool used when applying hot-melt adhesive to ensure tight seams in flooring installations, particularly with carpet. It functions by pressing and rolling over the seams, which helps to thoroughly bond the edges of the flooring material together. This ensures a flat, even seam without gaps, which is crucial for both aesthetic quality and the durability of the installation.

The other tools mentioned serve different purposes. For instance, a knee kicker is primarily used to position carpet during installation, helping to stretch it into place but not specifically for sealing seams. A power stretcher is also used to stretch carpet, particularly large areas, to prevent buckling but does not focus on seam tightness. Lastly, a vacuum cooling tool is used in specific applications, like cooling adhesive quickly, but does not aid in securing seams directly.

Therefore, the seam roller is the most appropriate tool for achieving tight seams when applying hot-melt adhesive.