By following our usual forming practices we are painfully aware that the corners we are getting are not sharp enough on a decorative concrete job. We have taken care to see that our forms are clean and well prepared with form release agent. How does one make sure that corners will be sharp?
It is important to see that all butt joints are properly gasketed and drawn up tight so that there is no leakage. Many architects and contractors, however, prefer to use chamfered corners because they do not show up defects nearly as badly. Various applicable methods for sealing corner butt joints in plywood forming systems are illustrated in the sketches.