for the edges buy "glue down" seam sealer (not white latex) from a carpet supply store. tell them you also need exterior glue to carpet your back porch. usually comes in a metal bucket, like a bucket of roof patch, stinks like hell, use the proper spaced trowel. spreads like caramel...wear a glove or the trowel will blister your hand from trying to spread it. cut an 18" scrap piece of 2x4 and round off the edges with sandpaper, a file, or a router. this will serve as your 80# roller. use the board to apply pressure for glue transfer and to lightly stretch as well as remove bubbles. i'll post more to help you out but i gotta go. fyi, 20+ years exp, master flooring mechanic speaking. get the right glue and we'll go from there.