OSB Warning To the Editor: Larry Schmuckler's article, "OSB: Job-Site Report" (JLC, 4/90), describes his use of oriented-strand board (OSB). In it, he acknowledges that the exterior grade OSB he uses for floors and roofs does not always withstand one soaking. He then continues to mention that he had to sand the board in one case, presumably to get a smooth surface for installation of the covering materials, and that other boards delaminated. OSB should not be used in locations where repeated wetting is likely, for the reasons of delamination and swelling, as Mr. Schmuckler observed. Such installations include roof decks and floors of bathrooms, kitchens, laundry rooms, etc. In these locations, it is important to use materials that can