|
Just remember, cast iron pipes fail from the inside out. I had a cast iron waste pipe in my last house from the mid 1940s. It had a handful of tiny little rust blooms on the outside. Like there were little pinholes in the pipe. In reality the entire thing was rusted out on the inside and barely holding on.
Given that it's only at the joints my guess is that the threading at those joints is rusting away, giving clearance for seepage past them.
Just given the age and that it's cast iron, my guess is that it's on the edge of failure. Best to replace. Easy DIY job for any above ground section.
|