Do you have the plans? These don't resemble what I build. I'm concerned about stringer spans, thread structural thickness and spans, etc.

Those are wedges used to tighten up the stringers and treads. I have seen them done this way many times. Why plywood treads however?

I'm assuming the stairs are carpeted but even so, this is crap. Why 1/2" sheeting for the risers? What is the thickness of the treads? The wedges are not hardwood which stair wedges should be. There's no center stringer so it's likely your squeaking is coming from weight as you go up/down near the center of the staircase - the treads and stringers are rubbing against each other - the wedges will do nothing for that. You have the perfect opportunity to see your stairs in action with the open back. Get under there with good light and have someone go up and down slowly - see your stairs in action. Where you see movement you will hear noise.

Jeffrey R Grenz, what are the concerns regarding the stringer spans, thread structural and spans?

millworkman, why are you concerned about plywood treads?

Each tread and riser fits into a dado in each of the stringers. The dados are tapered to accommodate a wedge at the same taper. There should be intermediate stinger(s) to support the treads mid-span, or at least blocking under the treads to help distribute the load to the riser. In my opinion, what you show is a poor way to construct stairs, unless there is something structural above the stair not shown (but I doubt it).

I'm thinking we're concerned because you posted issues. Its easier to analyze with photos and structural directions.

My specs are 2x12 stringers 16" OC max braced 8' OC max.

I don't see intermediate stringers, I'm guessing it would take two more.

It takes plywood thicker than I've ever seen to make spans the entire width of that stairway, unless your structural engineer has a scheme tying the entire unit together with construction adhesive, in which case there would be calcs... but I doubt it. This "technique" is new to me.

Were permits and inspections required?

Yes, I raised this issue because the stairs are creaking already. No, I don’t have access to the plans. By the way, this is a straight staircase with 16 stairs. Mark, when you say “blocking“ under the treads, do you mean like in this picture (not my stairs)? Jeffrey, when you say “intermediate stringers”, do you mean like this second picture? Just before we moved in, the builder added an upright 2”x6” (?) on one side under stair 6 and on the other side under stair 8.

I appreciate your help. I am trying to understand what the problem might be because I think this may be a warranty issue.

Definitely a warranty issue.

The stringer is the large 2x member on the side of the stair. There should be more of them most likely. The plywood stem is spanning way beyond its capabilities IMHO.

Unless the builder can product approved specifications that meet code, I'm not liking what I see. Where is the stair located?

This image shows how these typically go together. The riser supports the back of the tread below, and the front of the tread above eliminating the need for center stringers.

Jeffrey, the staircase runs from the front to the back of the house, which is a bungalow.

Thank, everyone. You’ve all been really helpful. Wish us luck in dealing with the builder - or else the warranty program.

Here is the relevant section in the Performance Guidelines under the warranty programme I've built under.

Donlar, as PPF & Worthy pointed out, this is a common and legitimate construction method (that I was not familiar with - wow). The fixes may be as simple as tightening wedges or not. 1"+ plywood threads can do that span.

I have the same problem. I just moved in October 2023 and my stairs already squeak. I don’t think the stairs are done correctly based on other pictures of homes. DRB homes did a horrible job at everything, especially my stairs.

DRB Homes

More DRB Homes “Quality”

It almost was me, please go their homes being built in the framing stage in construction. Take pictures review.
800,000 home. They don’t care