Question on stair rebuild with new treads

[Turtlewood]

Hey All,

I've started the process of tearing up my old stairs treads and replacing them with hardwood treads.

The stairs were covered in carpeting down the center 28" wide with 4" stained pine "accents" on each side. I've removed the carpeting, the side accent pieces, and the particle board risers.

Attached is a photo of the stairs in their current condition:

The basic structure of the treads are simply two 2x4's laying on their side, one in the front and one in the back with 1/2 inch plywood on top. You can see this best on the top tread in the photo from underneath. The net thickness of the treads is 2" (1.5" of 2x4 and 0.5" of plywood)

Don't be fooled by the shadows on the side, the stain marks show the hight of the decorative 4" endcaps. The majority of the tread hight was the top of the plywood plus whatever the thickness of the carpeting was (there was no padding). The stairs feel "right" walking up them now as shown, there is no odd step at the landing. So basically my intent is to maintain the current hight marked by the top of the plywood.

My plan is to install 1" thick solid hardwood treads. This leaves me with a 1" gap in thickness/height when I remove whats there as I plan to maintain the current tread high.

So what's the best thing to do? I'm guessing adding 1" thick shims the same width of the stringers, but I'd greatly appreciate the experience and input of folks who've come across this issue before.

My main concern is that adding 1" thick booster shims will create another seam/gap that may squeak, and possibly weaken the structure too much?

Comments and suggestions greatly appreciated!

Thanks,
-Kevin

 

[NCPete]

Kevin, I would install the new treads and risers right over the current construction, with a 3/4" thick material. That will give you a solid step, which shouldn't move or squeak.

 

[FredP]

I would remove the 2x4's and plywood. then mill the 2x4's to 1" thick and put them back. use construction adhesive to eliminate squeaks. then go over top with your 1" treads and 3/4" risers. use construction adhesive on these too including at the joint between risers and treads. if staining the stairs use screws and plugs.

 

[FredP]

Kevin, I would install the new treads and risers right over the current construction, with a 3/4" thick material. That will give you a solid step, which shouldn't move or squeak.

if you do this the bottom step will be taller. it may take you out of code depending on the rise that is there now. it will also make the top step shorter unless he is changing the floor covering upstairs. odd rises lead to trip hazards.

 

[Gotcha6]

If the bottom and top risers are equal after the new treads are installed, go with Fred's suggestion. If not, adjust the risers to an equal height all the way up. No more than 1/4" difference in any riser & no more than 1/8" in any adjoining risers. Also, start at the top working your way down. Put a slight bevel to the top of the riser and the back of the tread so they mate up. Push the riser up tight against the tread above & then set the next tread. The bottom of the riser should go below the back of the tread - not on top. This way you get the full tread width on each step. You may also look into using Polyurethane construction adhesive & 2-1/2" trim screws for the treads. If you're careful, a couple of screws into the top of the riser from the tread will help too. A word of warning on the trim screws: be sure you don't have to back them out. The heads will tear the wood around the entry point if you do. DAMHIKT
Good luck.