I was looking at an estimate to install flashing on my chimney. The price was a bit higher that I expected. The contractor tells me that he adds "hot mops" around the chimney and then installs the flashing on top. Does this make sense to any of you?. I have read some tutorials online where "tape" is used to prevent water leaks around the chimney. Is hot mopping recommended or will "tape" be sufficient to prevent water leaks when installing flashing?