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Cost - New Interior Stairs

scarbelly's picture

Before having a contractor come out, I am trying to roughly estimate the cost of installing a brand new set of stairs from my living room down to our daylight basement. I'm trying to make it feel more like a two story house rather than the existing dank basement stairway. When I say new, I mean cutting an opening in the 2nd floor for the stairs. The house is a rambler in the Seattle area with a bearing wall running through the center. I'm proposing the stairs as a straight run parallel to and along the bearing wall. This means the 2nd floor joists that are currently sistered at the bearing wall will need to be cut and supported by hangers on a new beam (4 or 6x12) and posts to create the opening.

I'd likely finish the stairs with white oak flooring like the rest of the 2nd floor. I would do the project myself, although I don't think my family would tolerate my 6 month construction schedule considering other obligations. Here's is what I envision being involved in the project.

Sawcut holes in basement slab for two to three new footings (need waterstop around joint) - 1.5 days

Shore 2nd floor joists and cut hole in 2nd floor - 1 day

Install beam and hangers for cut joists on top of decorative posts integrated with stair railing - 1 day

Install stairway - 2 days

Finish 2nd floor opening, stairs and railing - 3 days

Any ideas on what something like this costs? I don't have much of an idea, but I am thinking it is 8 to 10 days with 1 or 2 guys. $10k? Any input is very much appreciated.

Thanks, Eric

Eric (post #206942, reply #1 of 9)

With all due respect-

I'd question your wanting to use white oak flooring.  White oak sure, but to use flooring for the finish I don't think the right move.

After that-being 2000 miles away and not quite sure of the finish in your description.........nor knowing the logistics of your area, I'd be hard pressed to offer an idea of a cost.  You are certainly not a cheap s.o.b. with a potential budget of 10 grand.

We do have a good carpenter or two on the board from the state of Washington, maybe I can get one of them to check in here and hazard a guess.


Your best bet by far, is to find some good remodeler with an A+ rating near you and consult with them.


Best of luck.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Very hard to estimate (post #206942, reply #2 of 9)

without seeing the house, but I give you credit for coming up with a $10K figure rather than thinking it's a couple thousand. 10 seems like the right ballpark. The framing part is probably the easy part, the finishes take more time and money. The only way you're going to know is to get a few contractors out there to look at it. Give them all the same details so you get some consistency to the responses. Pick a person/company rather than an initial number.

My swag would be that you're (post #206942, reply #3 of 9)

My swag would be that you're short by a day or two and a person or two.  The BLS says the average hourly wage for a carpenter is $19.  But of course working through a contractor you can figure maybe 50% "overhead" (insurance, taxes, bookkeeping, oversight, etc).  And someone needs to be paid for the engineering work -- non-trivial.

A swag on a swag gets to about $8K labor, plus materials and engineering work.  But it could easily be twice that, or 50% less.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Before bothering any (post #206942, reply #4 of 9)

Before bothering any contractors I think you will be better served to get the remodel design (plans & specs) down on paper and ideally approved (get a building permit) by the city. This may require opening up a few walls and ceilings to confirm the existing structure. Then a contractor will know what to bid on. Without real plans, he will only be guessing. Houses have the habit of springing nasty surprises. If you can mitigate these at the beginning, everyone will be better off. 


Thanks all (post #206942, reply #5 of 9)

I'm an SE, so I will do the engineering, plans and permit no problem. Thanks for the carpentry rate and other advice. It gives me at least some confidence I am in the ballpark. I agree that the finish work is where most of the time and cost will be. It will depend on what I spec and who I hire. I imagine a good finish carpenter is going to be more than $19/hr.

Regarding the white oak stair treads, maybe I misspoke. Are you saying not to use white oak for the treads, or not to use flooring? My mistake I think.

Labor rate (post #206942, reply #6 of 9)

I would expect good contractors to run $45-65 per man-hour. I'm not far from you and that's what it is here. Of course you can get cash-under-the-table guys for lower, but I wouldn't recommend it.

White oak treads are fine, but I would rather use solid 5/4" material (probably glued up into 12" treads) than use flooring to make treads. You can use flooring on a landing, if any, but you need a nosing.

Flooring for Treads...... (post #206942, reply #7 of 9)

I meant what David is saying-use white oak for sure, just don't use your flooring to make them up.

5x4 white oak is the ticket.

Best of luck.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Your question doesn't make (post #206942, reply #8 of 9)

Your question doesn't make much sense to me. Don't you have an existing stair to the basement? Are you putting the stairs in a different location? Why would you have to cut an opening in the second floor joists? Openings for stairs don't require any posts if framed properly. What are you talking about with footings and such? A properly framed opening is self supporting.

Beat it to fit / Paint it to match