Notes From The Field
06.15.2007 | PLUMBING
CAST IRON DRAIN LINES
Cast iron drain lines were commonly installed in houses until the 1940's and World War II. The WW II US war effort required all available iron and during the war, we switched to Orangeburg. (If you do encounter Orangeburg, it wasn't designed to last long and probably needs to be replaced if it hasn't already.) After the war was over, plumbers began installing cast iron again, and it was used until the 1970's, though we usually see ABS in 1960's and 70's houses.
Click for bigger image. Exploding cast iron drain pipe in 40 year old house.
While cast iron has a long life expectancy, most cast iron drains you find are already 40 - 50 years old or older, and at the end of it useful life. Since we can not see the lines underground, and the fact that it normally rusts from the inside out, you should always recommend that a plumber camera any cast iron drain line. Replacing drain lines from the house to the street is expensive and can run from $3,0000 to over $10,000 (if far and deep). Therefore, it is prudent to always recommend further investigation by a qualified and licensed plumbing contractor when you find cast iron drain lines. If you would like to find other tips and a home inspector's outline for performing the plumbing portion of a home inspection, check out our plumbing course, The Basic Plumbing Inspection. i-Course provides home inspection training for home inspection professionals. We have state approved home inspection continuing education courses.