I am in the process of renovating my house. Part of this was removing the plumbing system down to the stack in the basement floor. The house had a full bathroom in the basement and I no longer want it. I have cut open the concrete floor to expose the cast iron drain fittings. My question is the proper way to cap these pipes. Can I just use a rubber cap w/ stainless pipe clamp then bury and concrete over it? Thanks for the help.

In my area, by code you cannot just use rubber cap with clamp.

If possible you should use no-hub cast iron caps (available at plumbing supply stores) and clamp them on. See pics. These will never fail even with extreme pressures.. such as if the sewer backed up.

The rubber caps are usually fine, but can fail on occasion... so that when sewer backs up some may be able to seep out a weak spot in rubber cap and spill into the dirt.

Anyway, from where I stand... the rubber cap and clamp are fine... From code perspective, got to go with the cap and clamp pictured.

Thanks for the info. I'm right over the border in New Hampshire, not sure the difference between Mass. And NH code. Thanks a bunch.