Had sliding doors replaced. They left the old aluminum sill pan in place and put some black tarry caulk - Butyl I think they called it. No bithathane on the bottom, just over the sides and top over the face of the slider. (the website won't let me spell bithathane correctly)
The also replaced some windows, without a bithathane sill pan. I had to show them a youtube video showing how people do it, and made them take out the window and put one in. I talked to person in charge of the store and he said using the butyl is the standard way to install windows and sliders, not a bithathane sill pan. From what it seems like using butyl only is using the old way.
Will I be ok?