Can Grease Affect a Cast Iron Pipe?

Problems

• When oil, butter, salad dressing or sauces are poured down the sink, the grease from these foods can stick to the cast iron pipes. Over time, the grease builds up in the pipe and can, in severe cases, completely block the pipe, causing sewer overflows or backups. Grease won't cause long term damage to cast iron pipes, although a clogged pipe can be a significant hassle.

Prevention

• Even the most fastidious housekeeper will probably eventually have clogged pipes, but you can minimize the chances by scraping food into the trash and installing a filter in the sink's drain so food doesn't fall into the pipe. Never pour oil, bacon fat or meat drippings down the drain. Instead, allow these to cool, pouring into a folded piece of newspaper or disposable plastic cup instead of down the drain.

Solutions

• Commercial drain cleaning products use strong cleaners to break up grease and hair, dissolving clogs in kitchen and bathroom drains. However, they can corrode oil cast iron pipes so read the directions carefully before use. A plunger can often dislodge a clog adequately. If the plunger doesn't work, try an auger, which uses a retractable rod to push clogs out of the pipe.

Considerations

• Most homes built before the 1960s have cast iron pipes -- some are more than 100 years old. Old cast iron pipes may leak as they become worn or rusty. Small surface cracks may appear and will slowly spread unless replaced. These concerns are not due to grease in the pipes, but from normal wear. Replace old pipes quickly to prevent water damage and to avoid major repairs.