Doing a flat roof for myself at moment and have a concrete base with wooden upstands. I have primed the whole roof and leaving to dry until tomorrow. I have a torch underlay to go on first and then a mineral torch cap sheet, so a two layer felt roof. Is it best to run the underlay straight up to under the termination strip (an alluminium strip at the end with a lip) and then the top layer straight into the lip. Or should I lay the top sheet up to the bottom of the upstand and then lay a strip at the end of the run covering the upstand and into the lip of the alluminium strip and also covering the top sheet. So the last piece is about a foot long to finish off the ends. Or should tboth sheets be laid to under the termination strip and then a final piece be laid over the top sheet (about a foot long) and then tucked into the termination strip. Thanks for any help.