Greetings, this weekend my wife and I are taking Friday off to tackle this project. First some background: we have a 1929 story and a half home and from everything we can tell the upstairs (or half story) was refinished or finished in the 1960s, although there are radiators upstairs tied into the main heating system. The stairs match the flooring upstairs which is douglas fir. They have seen better days and from what I know about fir, it is not a hard wood that makes sense for stairs.
So I've ordered and received new red oak stair treads, they are larger than the existing treads and will need to be cut and finished, but they already have a bullnose edge. For the risers, my plan is to pickup some pine board of the same length to replace with. We plan on painting the risers white and finishing the red oak to match the main level hardwood floors.
I plan on using a 16 gauge finish nailer with 2.5" nails and then also using construction glue. Does that sound right? Do I need to pre-drill holes for the finish nails?
Do I need an expansion gap?
I plan to work from the top and move down, but we have a oak landing area that I plan on sanding/re-finishing later. Is there an easy way to replace the riser below it without taking all the boards up?
The existing treads are nailed in on each side and middle, then the back area was finish nailed, any easy way to remove them?
I recently re-did the stairs in my home, as in ripped them out turmed them 180 degrees and put them back. I finished them the way you are planning, Clear pine risers painted white and finished red oak treads. I started at the bottom and worked up as I put the treads and risers on. If you can get to the back side of the stringers the best way to attach the risers and treads is from the back with screws. Use flooring adhesive as well. If that is not practical then I would probably predrill holes and use trim screws plus floor glue. Then fill your screw hole with putty to match your stain. If you elect to stay with your 16 ga nails then I would experiment with a drop after you trim your tread to see if splitting is a problem. I have put on a considerable amount of 3/4" oak trim and had no splitting problem. I am not a fan of the finish gun only because of concern that eventually things will work loose even with the glue. I have never been around steps fastened that way so it might be OK.
The riser below the landing should come off without taking the landing boards up. If there nails through the floor boards into the riser and you can't do anything else cut the riser in half parallel to the tread with a reciprocating saw and pry it down and away from the floor. Cut off any nails left sticking down with a pair of heavy wire cutters before installing the new riser.
If your house is really dry and your treads are really dry you could leave just a bit of expansion room but don't get carried away. You have less than 4' of wood to expand.
As far as removing the old treads and risers I would say if you are not wanting to save anything get out the reciprcating saw and make life easy. But be careful about any twisting action as you can pop a point off of your stringer pretty easily, particularly the center one which has no lateral support. Work carefully and gently until you see how hard things are coming apart. If you get the first riser off you might be able to pry between the stringer and the tread with a flat bar and get the nail heads up enough to pull them. Be flexible and experiment.
Hope I answered a least a couple of questions. Fire back if something is not clear.
Been in remodeling business all my life. Best advice I can give on stairs is to always glue the risers to the back of the treads and screw or nail. 16ga nail gun works fine. The main thing is the glue. Make sure to glue the treads to the stringers and nail good. Check the stringers for cracks or splits which is common with old stringers. If so splice over with glue and wood. Number one rule for stairs is glue glue glue glue. If not you'll have squeeky stairs.
However nothing was square so I'll be puttying and chaulking a bit.
Sorry, should have warned you about that. I had to cut every step with a different angle slightly off of 90 degrees to eliminate the slight gaps. I used a sliding compound miter saw to accomplish that.
From your picture everything looks good though. Nice job.