Many homes, especially outside of the high sun states, use a rubber grommet as the seal to the roof. This is indicated by a black rubber ring with the vent pipe sticking out, usually white. A CQ is not designed to do much with these, although it can be used for cosmetic reasons to make the roof look better and does keep animals out of your plumbing. There are products availible designed for rubber flashing, but always check the condition of the rubber before you do anything. Even in low sun cool or cold states rubber flashing will dry and crack over time, and this can cause some serious leaks. Lead flashing will last much longer, but needs to be protected with a CQ.