Replacing already tiled floor doesn't give back materials

[Pichu0102]

A15.
This bug occurs if you try to place a different flooring over floor you've already built. Normally, removing flooring returns materials. However, placing new flooring over existing flooring doesn't return materials from the floor that was replaced.
I'm not sure which of my mods are doing this. I've got:

Allow Tool
RimFridge
Cooks Can Refuel
Muzzy-Utils
EdB Prepare Carefully
OSHA Compliance
JTReplaceWalls
QualityBuilder
Achtung! Mod v1.3
Where is rich soil?
RT Fuse
Blueprints
Core Driller
Hand Me That Brick
Refactored Work Priorities
A Dog Said...
Expanded Prosthetics and Organ Engineering
RT Quantum Storage
Wildlife Tab
Miniaturization
Efficient Light
PetFollow
Feed The Colonists
Misc. Robots
Better PAthfinding
PetMute
Look At Me, I'm The Worker Now
HuntersSpot
Auto Seller

Not sure which one is causing this behavior...

[14m1337]

I think this is vanilla behavior

[nccvoyager]

Indeed, this is vanilla behaviour.
This may be WAD, though as just a player, I cannot say for certain.

[14m1337]

and it's not even unrealistic behavior. I know of many situations (for example when renovating an old building) where the old floor was left and the new floor was just installed on top.

[nccvoyager]

This is true.
However, the way it is modeled in-game, placing a "wood" floor atop a "sterile tile" floor will permanently remove the sterile tile floor.
If the wood floor is later removed, no resources will be returned from the sterile tile floor, and the sterile floor tile will not be revealed to have been "under" the wood tile.

[Rock5]

When you build over a wall, eg. with a door or vent, you get the materials back. So I would expect the same behavior with floors.

So I think this is a bug and will eventually be read by someone who can flag it for attention.

[Illusion Distort]

Vanilla behavior. You can gain the resources back by using "Remove floor".

NOTE: The floors under the walls are (under the walls), when the walls are removed, the floors will be visible again. Not a bug, just some unclear behavior.

[Rock5]

Ah, of course. I forgot walls go on top of floors.