A chat with an old timer at the supply yard flipped my view on seam rollers
I was picking up some padding in Cincinnati last week and got talking to a guy who's been laying carpet since the 80s. He said, 'Kid, a heavy roller isn't about weight, it's about the heat you build up from going over it enough times.' I always used a light touch to avoid crushing the pile, but I tried his method on a glue-down job yesterday, doing five full passes per seam. The seam practically vanished. How many passes do you all usually do?
That old timer's advice works on glue down, but it's a different story with stretch in. I've been doing this since 1995 and I only do two passes, maybe three if the seam is being stubborn. More passes than that on a stretch install just risks stretching the carpet out of shape at the seam line. You get a flat seam but a visible dip later. The heat helps, but you can overwork it.
Start piling on the passes like that old timer said. I was using a light roller forever and always had to fight seams. Switched to a heavier one and did six passes on a glue down job last week. The seam disappeared. You just gotta feel when the carpet tells you it's done though, every job is different.