I can’t quite decide where to put this question; it is quite trivial and to a certain extent, it’s asking for opinions, however, I feel sure there is actually a set of objective factual answers.
I have to re-roof a small area of felted flat roof over an oriel window; there appear to be two options for flashing at the junction of roof and wall:
-Traditional lead flashing, pointed into the brickwork.
-Butyl or other plastic flashing; apparently applied in two layers; a highly adhsive tarry layer and a second waterproof top layer.
How do these non-lead flashing tapes perform in comparison to traditional lead? It’s tempting just to write them off as a cheap, short-lived solution, and indeed if there’s evidence to support that, then that’s what I’ll do, but what are they like, and do they actually work at all?