A high, wet wind blew off a half-dozen shingles or shingle parts the other day. A roofer came out and replaced what was necessary. Another high, wet wind blew a day later. The replaced shingles were virtually standing on edge (like speed brakes on a jet plane). After taking a peek of things, I conclude:
There's a supposedly adhesive strip applied by the manufacturer to the top side of the shingle, running length-wise edge to edge, sometimes not solid but rather dashed (as in a dashed line).
This supposedly adhesive strip is probably made out of a tar-like substance. It's certainly not sticky at 65-degree(F). And there's certainly not enough of a bead to satisfy my Electronic Engineering sense of building construction.
So how long does it take for one shingle to adhere to the one below it, or, at least, what's the best approach to preventing the lifting of "not yet sticky enough to adhere" shingles?
(Sacramento Valley, California)