The potential problems with removal of runner are dependent upon how the runner was installed. Some dearies actually tack the runner to the steps, tread and riser. Ouch, because removal leaves those holes to be filled and stained to match (very difficult to conceal). An alternative method is to use carpet bars which come in wood or metal, in an assortment of finishes. This is slightly more expensive but imo, also *looks* more luxurious. The carpet is barred at the back of the tread where it meets the riser; best practice has the runner tacked beneath each tread rather than slanted from top-front to the back of the next lower riser. Note that under-tread tacking also uses the most running feet of carpet, so the most finished appearance is going to cost. There are several other methods, so discuss intent with the installer before s/he does the work. One thing for sure, is to not use any sort of sticky-back tape: it either doesn't hold well, or holds too well and removel is labor-intensive. Because of the carpet pile height, if possible choose treads that are slightly deeper than usual so as to maintain fully safe depth.

There are various types and it works fine for a variety of types of flooring.

In 1800s-early 1900s houses, it was common to have different woods on floors ... with the degree of expensiveness declining as you went away from public areas. I lived near one house where the flooring changed from rare hardwoods (inlaid, of course) in the areas visitors would see, to good oak in the family's bedrooms and private areas, to pine planks in the servants quarters. The moldings going up the staircases declined in ornateness with each floor, too. Carved walnut became less ornate oak became plain poplar painted wainscoting as you went up. Often the lower floor's flooring was continued up a staircase, with the change taking place as you stepped onto the next floor. Or at least until the wood was out of sight of the guests ... I have seen staircases where the switch happened at the landing because the upper part of the stairs was out of sight. "The stairs go halfway up to a landing, then 180 degree turn to go up the rest of the way, if that matters. " Take some photos and spend time with an editing software: maybe light wood on the stairs would be a nice contrast, maybe not. Maybe painting the risers to match the moldings and having dark tread would look best. Or match the risers to the lower floor color and the treads to the upper floor Lots of choices and none of them are "wrong".

If you are looking to do a decorative carpet on the stairs (only) then one way to do it is to use the carpet as a RUNNER...not a stringer-stringer carpeting. The other thing to consider is normally the stairs should match "something". If you have different carpet at the top of the stairs that does not match the stair carpet, that NORMALLY means you have different carpet DOWN stairs. The stairs will match the carpeting on the MAIN floor. I'm not hearing that this is your scenario. What type of flooring do you have on the main floor? This is what the stairs will be MATCHING if you choose to go this route (stairs not matching carpet upstairs). The other way to do this is to use the decorative carpet on the stairs and then pay to have an area rug cut and bound in your chosen "stair" carpet. This area rug then sits in the entrance/bottom of the stairs. This is a quick, easy (slightly less expensive) way to get the stairs to match "something".....'cause they really should match something. Right now they match the upstairs carpet. Once you change this design feature, you need to REPLACE it with another version of "must match something". The bound area rug in the same carpet is one of the fastest ways to do this. Good luck. Remember to look at your main level flooring and decide whether or not you want to go forward with this concept.