A method and apparatus for sealing a cut edge of a foam board is disclosed. The foam board has a top surface, a bottom surface, a first cut edge and a second cut edge. Each cut edge extends between the top and bottom surface. The method includes heating of at least one of cut edges to raise the surface to a first temperature, applying pressure to the at least one of the cut edges by a pressure source at a first pressure, and cooling the at least one of the cut edges to a second temperature. The first temperature is above the foam glass transition temperature and the second temperature is below the glass transition temperature.