I used copydex to keep the strands to the back then heat seam the join,then F3 to the underlay.Takes a long time but you get no fraying,and it looks good.....to make things worst the whole job had no skirtings,but shadow gaps instead
Only very slight,before I done the seam I pushed the strands really tight to the carpet,then done the seam on hardboard and rolled it with a flat roller as I was seaming,let it cool then stuck the whole lot with F3