I have a steel pole holding up part of my house. It is bolted to concrete footings. I am about to build a deck around but would like to rust-proof the bottom before I do this to prevent any future issues.
Given that the bottom 30cm will not be visible, what is the best way I can ensure it will not rust? I was thinking some Kill-Rust primer and possibly some bitumen paint to keep the water away.
DA01 is correct about direct contact with concrete to a point. If the steel and concrete are above ground grade and the concrete is beveled enough for any water to run off or not collect around the pipe, then serious rusting will take a very long time. As far as rust proofing the steel pipe, clean the metal very well. Sand off any paint or other materials. Prime the steel with a zinc chromate primer. This is available in spray cans from Krylon. After 24 hours, coat the surfaces with truck bed liner. You can buy truck bed liner in either brush on or spray on cans. Use a couple of thin coats and overlap the bed liner down and over the concrete. This will give you a great water/moisture proof covering. Good luck
If it's in direct contact of the concrete, note that you may eventually have issues there (as concrete can easily wick up ground moisture).
If you lay concrete, ensure that the concrete laid with the high point against the post. this will ensure that water pooling does not happen around the metal pole.. you will still get rust, this is one way to prevent to a degree.
I would coat the bottom part of the pole with roofing tar, similar to what can be done when setting wooden posts for decks. You can get different sizes too - like a caulking tube size. Apply it with a putty knife.
Do you have anyone locally who does powder coating? Powder coat paint can sometimes be cheaper than you might think and will really help keep the rust away for a while.
