My guess is no. We had carpet installed on our stairs and our upstairs hallway and bedrooms. The carpet install was "free" though we had to pay extra for the stairs.
When vacuuming the steps the dust-buster lifted the carpet on one of the steps. This also revealed the installers didn't replace the 30 year old damaged tack strip. The little nails on this exposed tack strip aren't at the 45 degree angle that they should be but are mostly pointing straight up.
Which leads me to my next point (pun). In multiple locations the tack strips are easily poking through the carpet. The worst area is where the carpet meets the laundry room, where the carpet transitions to linoleum. The tack strip is an inch from the silver metal piece. The installers actually tried to leave the metal transition piece until my wife remembered paying for that silver metal transition.
The carpet in general seems to be shedding. On the window seats in our children's room there are strings hanging from the carpet.
We purchased the best padding the store had and what we thought was mid range carpet.
When the old carpet is pulled up wouldn't that bend the tacks up so that they point upwards making them a hazard? They should have replaced the old tack strips, right?
Should the carpet on the steps be a single piece or at least sewn together?
Update:
imgur.com put in some weird images instead of mine so this is a link to a flickr set of the carpet issues:
http://www.flickr.com/photos/31260465@N04/sets/72157637395611156/show/
Best Answer
Nope, your carpets weren't installed correctly. I'm not sure if code dictates that tack strips need to be replaced, but at the minimum, your contractor should have checked if any tacks were poking through or would otherwise pose a needle hazard. Those things hurt.
Shedding seems to be normal. We recently had some carpet installed on our basement stairs, and some corners (and manually-cut straight edges) do have the little plastic strings hanging loose, and several nylon curlicues roaming around. I really wish all installers would properly vacuum their junk up, but most of them don't.
Carpet on the steps does not necessarily have to be a single piece, simply because you can start a new piece (and stop the old strip) where a tread and riser meet. As long as the edges are butted together with no gaps, you should be fine.
Also, simply vacuuming should not lift carpet edge off (anywhere, specifically not stairs!)... that alone should require that they come back and fix it, or pay for a professional to re-do the effort.