Do you mean that the creaking stops when you screw a vertical peg in that way?
Is the step solid wood? Most older stairs with a tread nose of some hardwood and a linoleum mat on the tread usually have a core of some softer pine or similar that flexes significantly under load. Best investigated by measuring deflection by borrowing a suitably heavy family member and a ruler (distance to step below with and without load)
I'm in the same situation with my staircase, so I wish I knew the ultimate solution. So far, I have reduced creaking by screw-gluing a support underneath that stiffens the construction. I tried screwing some steps from underneath at an angle into the stringer, but I still have some creaking left. More screws or other methods might reduce it slightly, but I think the root problems must come from flexing treads combined with how the tread attachment is made.
In your case, I would probably try replacing the molding underneath with something screw-glued upwards to stiffen the step and see what result that gives.
In your case, I would probably try replacing the molding underneath with something screw-glued upwards to stiffen the step and see what result that gives.
The treads are probably made of some composite material. Maybe it is a glue joint that has come apart. Investigating this and possibly replacing the treads is a comprehensive undertaking. Ideally, the entire staircase should be disassembled. Therefore, it might be worth trying what @myrstack suggests, to screw-glue a strip on edge under the treads. Timber measuring 35x70 mm should suffice.
F***ing pissstairs. What does it cost to replace the crap, 20 grand?
Tried to attach a brace under the step, something like 45x15. Made no difference, but it might have been me being useless at screwing too. I still thought it was pretty tight afterwards. It was attached with screws in both stringers and 2 under the step. Maybe it should just be attached to the step in case the stringer screw caused some trouble.
Can you hire an expert or is this the path you have to take? I.e., DIY or replace the steps.
Tried to attach a brace under the step, something like 45x15. Made no difference, but it might have been me being useless at screwing too. I still thought it was pretty tight afterwards. It was attached with screws in both stringers and 2 under the step. Maybe it should just be attached to the step in case the stringer screw caused some trouble.
Can you hire an expert or is this the path you have to take? I.e., DIY or replace the steps.
The trellis is well screwed into the stringer, so try to loosen the screws there so you can fold the trellis to the side, as behind it there are probably one or two screws going through the stringer and into the step, tighten the screws as much as possible. On the other side, which is against the wall, you won't be able to reach the screws without taking down the staircase. If you drill, for example, four or five 10 mm holes at the angle between the step and the stringer and insert glued wooden plugs, which can also be done on the other side, I believe the staircase will become silent.
