Removed carpet from stairs and planning on installing Young's RetroTread from Lowes over bare wood stair case. Many issues with these stairs because of how they were built. I have a very small budget so rebuilding the entire stair case is out of the question. Just have to get creative. Which I have done for the most part. However, existing bare frame wood steps are not level but rather pitched down almost a 1/4inch. They were not built the typical way a stair case was built. Whomever built them used a ton of nails and brackets. Shimming the bare wood steps or beating them straight is kind of out of the question. When I install the oak RetroTreads over the bare wood, I would like to find a way to make them level. Shimming in between the bare framming wood tread and the new overlay oak treads seems like the best idea so far but the only shims out there are the 1-2inch wide shims. It would take hundreds to do this job. Is there any way I can create 41inch wide shims with limited tools? Or can I find them somewhere? Or does anyone have another idea of how I can level the steps while installing the new oak treads over the existing bare wood steps?