Was there a reset in-between, and was your rental's appearance modified?
In this case... I can't really remember. It's possible it happened before or after yesterday's crash, I will endeavor to replace the tile under same conditions and see what happens.
This happened in my rental several months ago. I'm not sure exactly why/how it happens, but I've found that setting the z value to 0.02 has protected against this issue in all cases and visually differs from z 0.01 by a negligible amount since we generally can't get our camera angles low enough to visualize a gap between the carpet and the floor. (Probably obvious, I know, but I just wanted to toss it out there.)
EDIT to avoid double-posting; sorry:
I think the chair is a great idea. You should be able to purchase chairs like a normal person without having to have a carpentry skill, wood, and a kit on you at all times anyways. Bards use chairs the most, and they have to get a smiths apron to equip axes to even cut a tree.
Give the people chairs!
I like this idea and fully support it if it could work! However, I've noticed that basket and chest items placed into rentals sometimes get converted into indestructible placeables that have to be removed with @spawn destroy. (I think it's usually after a reset.) I don't know whether the chairs would end up the same way or whether it'd cause problems, but the risk seems pretty small. I'd say it's worth the attempt if it's possible.