I chose to use Grizzly Grip. Tried to document the process and will be doing a second coat within the next couple weeks I think. Am sure this process is similar no matter which roof coating is used, hence why sharing here.
One thing which disturbed me, not greatly, but still something to ponder, is that Grizzly Grip didn't soak through like HercuLiner did. It also caused some expanding of the dried underliner, which causes what looks like warping in the underlayment. Am not quite sure if it's extremely important to have a flat roof or the bubbles/warps are unimportant.
Overall am pleased how it all turned out. Have two posts related to this, one about cleaning and the other about the actual application. Once figure out what to do will have a third (maybe fourth) related to the final coat.
CleaningApplication
