Server: G-Portal Rented
This the setting that would remove decay on the Exiled Lands map.
With this same setting Isle of Siptah map shows a standard decay.
I placed a sandstone foundation block and then attached an insulated ceiling tile. I place an insulated pillar under the ceiling tile.
The decay time showing was 60 minutes.
I later added 10 more ceiling tiles and pillars (insulated T2) and removed the sandstone foundation block.
Now the decay timer shows: -
I am not sure why there was a 60 minute decay timer as I have a lone fish trap that is not near any building pieces and it showed the “-” as the decay timer.