Even the independent lumber yards don't seem to carry dry 2x12's. Only reason I hesitate to use green is because I'm putting in hardwood treads dadoed to risers so there isn't much room for things to adjust.

There is probably no alternative but does anyone know if green is typically used for stair carriages? Or I could purchase and wait for it to dry out.

Thanks

If you are refering to housed stringers (where the stringers are routed to receive the treads and risers) those are made of a 5/4" hardwood, usually of the species of wood used for the treads and risers. If you're refering to horses (carriages, notched stringers, etc.) you are correct that they are often made of 2x12 #2 or better doug fir framing stock. That is typically not available in KD. In typical construction, it is usually dry enough by the time the finished treads are installed ( framing first and finsh work last; 4 to 6 months ) All you can do is find the driest ones available and place them in a dry environment and wait till they dry out somewhat. A moisture meter will be needed to ensure suitability. Perhaps a local mill has a kiln and would allow you to purchase your material and dry it for a small fee. Good luck.

Thanks Gary, I was referring to the horses. I found dry 2x12's at 3 times the price of green. Worth the price though considering expense and effort going into staircase.

Now I found out that they charge $7 per board foot for 5/4 x 11" x 12' poplar for the housed stringer and mitered stringer (mitered stringer is 4/4). My total cost for the paint grade lumber (skirts + risers) for a 16 riser stair case is $700!

That's why you make your own using a jig and S4S lumber!

I'm sorry! I misunderstood your reply. As I understand it now, you will have one housed 5/4 stringer in poplar against a wall and the other side of the tread will be open with mitered risers to a mitered stringer on the open ended side. Correct? I just built one similar. Got to the photos section of this message board and look for Santos Mahagony Staircase and More Stair Pictures. I think I paid a little less for my poplar but it was still alot. Good luck

Thanks Gary. This is a challenging project for me but I just cannot stand carpeted stairs and that's about all you see in CA. My goal is a housed inside stringer. I have a book and an article that has good detail on how to do it. If it prooves to difficult I can revert back to a butted stringer and add one more carraige next to the wall but I'm fairly confident.

If I could ask a couple of related questions which have been bothering me -

1. I already installed MDF base in my upstairs so I will be sticking with that (it's Sierra 5 1/2" in case you know that base). I would really like my skirts to match the profile. So my plan is to round over the the skirts to roughly match the first roundover on the base. Then I will rip the profile part of the base off (about 1 1/2" tall) and glue/brad nail this onto the skirt. There will only be about 1/4" of contact between the ripped portion and the skirt so I'm not sure how practical this is (I'll experiment beforehand). Also, I'm mixing MDF and Poplar over 12' - do you think this will hold up? Or I suppose I could have knives made to match the base - what do you think?

2. I notice you do a lot of bordered floors - I also did a bordered floor with a Brazilian Cherry feature strip. I used biscuits on the mitered corners (cut the biscuit width down for the feature strip). The difficulty I had with 4" maple miters is often they would be tight when I glued the biscuits even with the board completely seated but when I nailed the board in with the blind nailer sometimes they opened up - often 1/8". In theory I could wait for the biscuit glue to dry and then nail the board but it would really slow me down. This is probably exacerbated by the wide boards and the fact that my wood sat in my house for several months before I started installing it (warped a little). I always undercut the bottom of the miter with a hand plane. I don't like to bevel the saw because I worry that gaps will show up on the sanding. Do you experience this and what if any solution is there?

Thanks for all of your excellent advice!

Question #1: the way you describe is the way I do it. Although I didn't round over the stringers. I ripped the top portion of the base just as it becomes the flat lower part and nailed that to the wall studs. I've had no problems. Keep in mind that this is the customary way of doing built-up baseboards and moldings. Mixing wood species doesn't matter except MDF isn't as durable but paints well.
Question #2: The way to keep inside miters tight while nailing is to put wedges behind the board so it can't move out on you when you nail it. I leave my wedges in till my borders are done then I remove them. Bisquits are good; as well as splines. It helps keep the surfaces flush and the miters intact. If you need a slight relief on the back to make the miters tight, thats fine. Since I use a very accurate saw and get my subfloors flat, I have not had the need to relief cut my miters. They're tight! A 1 or 2 degree back cut would not show upon sanding!