I'm working on the rust on the steel I-beams under my house (removing rust with brush and then hitting them with that rust converter and then cold galvanizing over everything when done) but I was thinking about how to prevent rust from occurring again.
As you can see in the pics the areas where the I-beam contacts the pylons the rust is significantly worse than anywhere else. Other areas it's just very minor spot rust, but there it's continuous rust and even flaking rust in some of the worst areas. I am still able to remove rust and get to shiny metal after some work, but I'd like to prevent this from coming back if at all possible. Since these bad areas are located where they are I'm assuming that the cause of the rust is water wicking up through the concrete to come into contact with the beam.
What I was thinking of doing was using PC Rot Terminator (or something similar if you guys know of something else that would work, especially if it's a bit cheaper ) to make the concrete brick around the contact areas waterproof. I was thinking that since it's designed to penetrate what it's applied to if I put enough on there it would soak to the point that it would contact underneath the beam and prevent water from getting to it. (If it wouldn't be able to penetrate that far I could always drill at a an angle from one side to create a entrance point for the epoxy, if you think that would help/be a good idea.)
Probably the more surefire thing for the beam would be to get a jack under there to lift the beams and put something impermeable (like vinyl flashing) between the beam the pylon, but I'd rather not do this since this is a 60 year old house and I'd sooner live with the rust coming back at its slow rate than risk the issues that might arise with trying to lift the beams. (Not to mention that I don't think I have a jack that could do that, so I'd end up hiring someone.)
Extra info in case I forgot it: House is in Oklahoma and was built in 1956; beams are galvanized steel (though all the zinc is gone on the bad rust areas); originally there were aluminum flashing termite guards between the beams and the pylons but they have rusted through; there has been virtually no movement of the foundation since it's been built.
To add: the reason I'm thinking of PC Rot Terminator even though it's wood hardener is because the label says it can be used for concrete as well, and all the other sealers for concrete that I've seen don't seem to be designed to distribute throughout the piece the way that is.