I have heard, but don't personally know, that Winnebago uses the sealant to hold the roof on and it must be replaced at regular intervals. Obviously a 1992 is not under warranty but the insurance companies also know. A buddy of mine who lives in Richmond, VA had the roof of his Itasca partially blow of during a storm this spring. The absolute first thing that the adjuster asked him was when was the last time he replaced the sealant. In his case it had only been about a month and he still had some partial tubes to show the adjuster. I don't think the timing of the question was just a coincidence.