Hello, I have come across the topic of rust again by another post. Find from the bottom floor everything is ok. Built 2005 The Stabi is still the most brownish after a few screws. Exhaust pipe is EDELSteel!! Different composition than the end pot (which is blank) = says the manufacturer. The tube behind it without rust is coated steel ~6 years under. What did you do from year of construction xy? What should you do or can you do? Edit the pictures updated again.