The "slates" look more like asphalt shingles according to DH today, I have shingled the right & left ends of the roof and the rear and begun the front, and it does look as though the lacquer layer was not sufficient to keep them stuck down without rippling and rippling makes them look like wimpy asphalt rather than sturdy slate.
I did try going back and regluing the edges down and where it worked they look better, so this is what I'll try before the last coat(s) of lacquer. It also looks as though I shall need more than seven sheets of construction paper "slates". If I were mathematically inclined (instead of arithmetically challenged) I would have figured the square inchage (miniaturist's version of square footage) area of the roof and figured out that way how many 9"x12" sheets of black construction paper I'd need to prepare. Mumble, mumble... If I don't have to make more sheets I ought to be finished roofing tomorrow & can start fitting the yard. If not, we all know what I'll be doing for a couple of more days :o <_<
complements of havanaholly