Rotten wood is just harder to light than traditional firewood. Yes it’s safe to burn rotten wood in an indoor fireplace. I recommend using regular firewood to start the fire or at the very least you’ll need to use some type of fire starter(that might not even work).
Laminate cabinets vs wood
Castle in the woods
Wooden crate for vegetables
Free photo Rotten wood Abstract, Burned, Fibers Free Download Jooinn