Wallpaper Woes in Chinese Restaurant

While waiting for my order to be ready, I couldn’t help but notice problems ….
Wallpaper starting to curl at the seams.
Wallpaper twisting in corners as the building shifts and drywall moves. This is pretty common in Houston.
Other signs of poorly maintained building and/or climate control issues.

Seam curling back. I believe this to be a lower-end solid vinyl wallpaper on a gritty paper backing – one of my least preferred types.
When the walls are not prepared correctly, and the paper is not hung properly, and when there is a lot of humidity (door left open, steam from kitchen getting into waiting area, A/C not running or turned off at night), humidity can enter into the seams and be wicked up by the paper backing. The paper expands and pushes away from the wall, causing the edges of the wallpaper to curl back.
The next step is that the vinyl surface can actually delaminate (come apart) from the paper backing. This is pretty impossible to repair.

At the very bottom, you can see the vinyl separating from the paper backing.

The wallpaper has been wrapped around this outside corner, and a new piece of paper overlapped on top of it. When this is done, with vinyl material, you’re supposed to use special vinyl-over-vinyl ( VOV ) adhesive, because regular wallpaper paste isn’t formulated to adhere to vinyl / plastic .
But even if the installer had used the correct adhesive, under humid conditions or with improper wall prep, the odds are that this wallpaper job will start to fail.
Also note dirt along the ceiling, and along the chair rail in the previous photo. General lack of maintenance and I am really suspecting lack of climate control.

The black smudges appear to be mildew coming from underneath the paper. Again, probably related to humidity.
Vinyl wallpaper is a sheet of plastic, and moisture can be trapped behind it. That can be a breeding ground for mold and mildew.
So why use vinyl wallpaper? Mainly because the surface is much more washable than most other types of wallpaper. In a business, washability is attractive.
But these property owners chose a low-end vinyl product, most likely skipped proper wall prep such as a wallpaper primer, and have not provided a hospitable environment for the paper.
There are other vinyl wallcoverings that would have held up better. For instance, vinyl on a scrim ( woven fabric ) backing, or the newer backing called non-woven , which has a 20% polyester content, and therefore less likely to wick up humidity.