Cast Iron Pipes in Florida Homes
What is tuberculation, and why does it keep clogging my drains?
Quick Answer
Tuberculation is the plumber's term for the rust barnacles that grow on the inside walls of aging cast iron pipes. This rough, hardened crust catches paper, hair, and grease, which is why clogs keep coming back no matter how many times the line gets cleared.
Rust that grows inward
As cast iron corrodes, the rust does not flake away. It builds up into a hard, bumpy mineral crust bonded to the pipe wall. Picture barnacles on a boat hull, except inside your drain line. By the time most homeowners notice slow drains or repeat backups, this buildup has often shrunk the working diameter of the pipe by 30 to 50 percent.
This is why snaking and even hydro jetting only buy time in old cast iron. They clear the blockage of the moment, but the rough crust that caused it is still there, already catching the next one. Water alone cannot remove tuberculation. It has to be mechanically removed with cutting chains and milling tools, a process called descaling.
Descaling is step one, not the fix
Descaling restores the pipe's diameter and flow, but the iron underneath is still corroding, and the crust grows back. That is why we pair descaling with a structural liner that seals the pipe permanently. Descaling is included in every Southeast Services lining project because the liner needs a clean surface to bond to.
The Homeowner Takeaway
If the same drain keeps clogging, the problem is almost never what went down it. It is the pipe itself, and clearing it again will not change that.
