Lift a corner of the carpet at the top of a flight, where the tack strip dies into the wall. What is under there is almost never a hardwood stair somebody covered up. It is the stair as it was framed: construction-grade softwood, or a strip cut from a sheathing panel, run long into the wall, bedded in adhesive and shot full of staples. Square front edge. No nosing. Knots, a mill stamp, a saw cut that wandered.
That is not a defect. Carpet was the finish. The stair was the thing under the finish, built to the standard of something nobody would ever look at.
So the project is not uncovering a staircase. It is one of two other things: adding a finished stair on top of a rough one, or taking the rough one out and building the real stair on the stringers. What the carpet is hiding decides which — not the photograph you saved.
What the carpet is hiding
Every flight we strip has a version of the same inventory. Not carelessness — a crew framing a carpeted stair is building a substrate and knows it.
- Staples and nail heads across the tread faces, at whatever spacing the gun landed. Every one comes out or gets set below the surface.
- Ridges of hardened adhesive where each tread meets its riser, reading as a hump under anything laid flat.
- Square-edged treads with no projection past the riser, or an edge broken with a sander because that was enough for carpet.
- Tread tops that are not in one plane. Stringers get cut on site, notch depths vary by a hair, and nobody feels a hair through pad and carpet.
- Glue blocks underneath that dried out and dropped off, or were never installed on that flight at all.
None of that stops a conversion. It does mean the surface you want to bond hardwood to is not flat, not clean and not where you assume — the same problem as any floor, with the same answer, which is that flatness gets measured after the covering comes off rather than guessed at with it on.
Skirt board, or drywall onto the tread
Look at where the tread runs into the wall. If a finished board follows the stringer line up the wall, you have a skirt and you are in good shape. New treads and risers die into a finished edge, and small deviations disappear behind it.
If the drywall simply returns down onto the tread, every new piece gets scribed to an edge nobody made straight — or a skirt goes over the drywall and stands proud of it, or the drywall gets cut back and a skirt set into the pocket. Three legitimate answers, three different amounts of work, one identical finished photograph. A quote that does not say which it assumed has a hole in it, and that hole is one of the ordinary causes of a change order here.
Two ways to get to wood
A retrofit cap is a thin hardwood tread with a nosing milled on the front edge, glued and pinned over the existing tread, with a matching skin over the old riser. The original stair keeps doing the structural work. The new material is a face. Good work when what is underneath is sound: less demolition, less dust, and a stair is not a room you can close off and walk around, which is worth weighing when you think about living in the house while the work happens.
What a cap asks in exchange is preparation. Every staple out. Every adhesive ridge scraped back. Every squeak dealt with. A cap is only as flat and as quiet as the tread it is stuck to, and once it is glued you are not getting back underneath it.
The other route is removal: old treads and risers come off, solid stock goes on the stringers. That is the answer when the treads are already shallow and cannot give up depth, when stringer cuts are out of plane badly enough that a cap would telegraph them, or when an open side needs proper mitered returns. More dust, more days with the flight out of service, and it puts eyes on the stringers — better found with the treads off than assumed with them on.
The two risers that change the moment you add thickness
This is the part that surprises people, and the reason the job belongs to a carpenter rather than a flooring installer.
Riser heights within a flight have to be consistent. Not roughly consistent — consistent within a tolerance the residential code puts a hard limit on, because this is a trip-hazard rule. Your foot learns the rhythm of a flight in the first couple of steps and then stops paying attention. The figure that applies to your house is the one the building department will hold you to. Ask them, not a blog, ours included.
Now lay a cap of some thickness on every tread. In the middle of the run, nothing happens: the tread you leave and the tread you arrive at both moved up the same amount, so the rise between them is unchanged. The trouble is at the ends.
The bottom riser is measured from the finished floor to the top of the first tread. That tread just got thicker. The floor did not. The bottom riser grew.
The top riser is measured from the last tread up to the floor above. That tread got thicker too, but the floor above did not — unless somebody caps the landing in matching material. The top riser shrank.
One riser tall and one short, at the two places where people are least careful. Whether both stay inside tolerance depends on what the flight measured before anyone touched it, and builder stairs often start with less margin than you would hope. The same arithmetic runs the other way in a basement, where a floor assembly over the slab lifts the bottom of the run instead — which is why headroom, landings and riser heights get settled early down there.
The fixes are ordinary. They just get chosen before material is ordered:
- Cap the upper landing in the same material, so the top riser keeps its height. Usually cleanest, and the reason landing nosing exists as a product.
- Machine the same thickness off the existing treads before capping. Precise work, available on some stairs and not others.
- Rebuild the bottom step — often easiest, because the bottom riser is already the odd one out in plenty of houses.
- Coordinate with the floor going down at the foot of the stair, so the two thicknesses get decided together instead of in sequence.
Ask anyone quoting your stair how they intend to handle the first and last riser. It is the fastest way to learn whether the person in front of you has built a staircase or has installed a floor.
Nosing, tread depth and the balustrade
The nosing is the lip that projects past the riser below it. Code sets a range for that projection and a limit on how much it may vary tread to tread, and it earns its keep — the nosing is the part your heel finds on the way down. A retrofit cap arrives with its nosing already milled, so the new nosing sits wherever the cap sits and effective tread depth moves with it. On a stair already at the shallow end of what is allowed, measure before discussing stain colors. Whether any of it needs an inspection depends on what else is going on in the house, and what triggers a permit here is better known before than after.
Pulling the carpet also tells you how the guard was built. On a lot of builder flights the balusters sit directly on the treads, so new material gets drilled and fitted around them, or the balusters come out and get reset. Not bad news — it is the cheapest moment you will ever have to swap plain spindles for iron, because the holes are open either way. If instead a shoe rail carries the balusters above the tread line, new material passes underneath and the guard is never disturbed. Handrail height is measured above the nosing, though, and that line just moved. Check it.
Squeaks are a now-or-never item
Carpet and pad hide a squeak. Wood announces one. A flight that is quiet under carpet will not be quiet in oak, and the squeak was always there. It was wearing a sweater.
A squeak is movement: tread against stringer, tread against riser, a glue block that let go, a wedge that dried and dropped. The repair depends on access. Where the underside is open, as it often is over an unfinished basement, we work from below with blocks, wedges and screws and nothing shows on the finished side. Where it is drywalled, the fix comes from above — screws into the stringers and the riser, counterbored and plugged, before any cap goes down.
Either way the window is open once. After a cap is glued and pinned, the squeak under it is permanent.
Matching wood that is already in the house
Most people converting a staircase have hardwood at the top of it, the bottom of it, or both, and want the stair to read as part of the same house. Species and cut are the easy half. Color and sheen are the hard half, because a floor that has sat in daylight for years has drifted from the color it was milled at. Material matched to a showroom sample will not match your floor. Matched to your floor, under the light in that room, it gets close.
Site finishing gives the most control: raw stock goes down, gets sanded with the surrounding floor if that floor is being touched anyway, and the stain is mixed to the room. Prefinished caps skip the dust and carry a hard factory coating, but the color is the color. If the floors are in play, whether yours can be refinished at all gets answered first — stair now, floor later usually means buying the same match twice, which is the argument for phasing so the second phase does not undo the first.
A cap is hardwood glued to a substrate that moves at a different rate, in a climate humid all summer and dry from the week the furnace starts. Wood moves here seasonally, and on a stair it shows at the skirt joint and where the cap meets the riser. Those joints get planned the way trim gets planned, not improvised at the end of a long day.
What actually moves the number
A flight running down to a basement is not really a stair project. It is the first thing anyone reads about the room at the bottom, so it gets scoped with the rest of the basement rather than as an errand afterwards. Same for a stair landing in an entry or a kitchen already being worked on: the flooring decision gets made once instead of twice, which is the argument for choosing flooring room by room.
We do not publish prices, because a number written before anyone has seen your stair is a guess. What swings it:
- How many treads, and whether the flight runs straight or turns.
- Winders — the pie-shaped treads at a turn. Each is a different shape, templated on its own, and the most expensive treads in any house.
- Open on one side, or closed on both. An open side wants a returned, mitered nosing on every tread. More bench time.
- Skirt or drywall return, and what the balustrade is doing.
- Site-finished or prefinished, and whether the floor around it is being refinished at the same time.
- What we find when the carpet comes off — the line nobody can price from the driveway.
That last one is why we look before quoting instead of after, and the same reason an itemized estimate is worth reading line by line: the lines that are missing tell you more than the lines that are there.
The short version
Under your carpet is a stair built to be covered. Converting it is a carpentry job with a code problem attached, and the code problem shows up at the first and last riser the moment you add thickness. That gets solved on paper, before anything is ordered.
Species, stain and iron balusters are preferences. Risers, nosing depth and squeaks are not.
Finish carpentry we have done sits on the projects page. If you want somebody to pull a corner of the carpet back and tell you what is under there, ask for an estimate and we will walk the flight with you.
