Question

Does a rejuvenation treatment void my shingle manufacturer warranty?

This is the question the whole industry avoids, so here is the straight version: it depends on the manufacturer, and you should check yours rather than take any contractor's word for it.

Most asphalt shingle manufacturer warranties are already limited and prorated by the time a roof is fifteen or twenty years old, which is the age range where rejuvenation makes sense. For a lot of homeowners there is very little warranty left to protect. But "very little" is not "none", and it is your call, not ours.

Find out who made your shingles, look up their written position on surface treatments, and decide from there. If we do not know the answer for your specific product, we will tell you we do not know.