I just had a local compamy install a new laminate countertop. I was surprised to see that the top laminate was left with a small radius in the internal corners (see picture). I asked the installer and he told me that this is a requirement of the laminate manufacturer and it has to be done this way for warranty reasons. In spite of voiding the warranty I am considering chiseling this radiys to a sharp corner. I understand the strength reasons for doing this but I would think that once it is in place there would be no stress on it. My old counter had sharp corners and there was never a problem. I would like ot hear the opinion of some industry professionals on this issue.
radius in corners is the ONLY way to go, sharp corners are a no no and if you had one that did not crack at the corner consider yourself a very very lucky person.
And yes, non-radiused corner will void any warranty.