Knee kicker vs power stretcher, 12 years late to the party
Used a knee kicker for every residential job since 2012 because my first boss said power stretchers were for mall stores and lazy hacks. Last month I finally borrowed one for a 15x20 living room in Des Moines with a nasty hump near the slider. Got the whole room flat in one pass without bruising my knee twice, so who else is still dragging their feet on upgrading?
Power stretchers aren't just for big commercial jobs, that's the part your old boss got wrong. The whole point is they pull from a fixed point across the room instead of pushing down at one spot, which is why that hump near the slider laid flat in one pass. A knee kicker mainly sets the carpet onto the tack strip, it was never built to stretch a 20 foot span. Plenty of resi guys run both, kicker to hook it and stretcher to actually pull it.
The fixed point thing is only half of it though, what really matters is having a solid anchor on the other end because if that wall plate slips even a little the whole stretch is shot. I've seen guys run a power stretcher into a weak wall plate and pop half the baseboard loose, then wonder why the carpet came back loose a month later. Kicker plus stretcher works, but only if you take five extra minutes to set up something the stretcher can actually pull against.