Expert: Bruce E. Johnson - 3/5/2009

Question
QUESTION: Hi Bruce, I had an addition put on my house that consisted of an open front basement which is the garage and a family room above that. The garage floor has a drain centered in it. Since we live in northern Vermont 7 months of the year we drive into the garage with snow and salt covered vehicles, which thaw in the heated garage and the floor is pitched properly so that the water goes to the drain. All is well with this part, but the problem is with one of the lally columns. It is positioned on the garage floor, not embedded in the concrete floor, but it does rest on a substantial concrete pad under the concrete floor. The problem is that the salty water mix running around and past this rear most post as it heads to the drain, has substantially rusted and corroded the bottom 5 inches of the lally column steel. It still feels solid but is very heavily rusted and corroded. You cannot yet see the concrete filling but I think it may be close in spots. I was going to paint the post with epoxy paint and buils a small box around it and fill it with a square of concrete to keep it tidy looking, but realized that concrete wicks moisture and may lead to further problems. I then thought about just some water plug concrete patch, which I don't think absorbs moisture, just tapered up from the floor to the thin flat steel base under the column? I don't thin this will keep the water far enough away to do much good. I need to get the corrosive water away from the post and somehow stop the rust that has started before it goes further. I just hope its not too late. Any advice would be very welcome.Concrete box, or other barriers you may know of? A good paint better then an epoxy?

ANSWER: Hi Rick, you are definitely on the right track.  First of all you can get a special paint that takes rust and turns it into primer.  That would be my first step.  Convert the rust so that it will not continue to deteriorate the column.   Then, epoxy is a pretty good coating so you are good there.  Then you can build a form around the column base a couple of inches deep and pour some non-shrink, non-metallic grout around the whole base and up the column the thickness of the form, preferably with a little positive drainage built onto it.  Let the grout cure for a couple of weeks and then prime and epoxy it to seal it.  Theres not much more you can do at that point.  I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com

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QUESTION: Thanks so much Bruce. One additional question: Grout? could you please recommend or advise me on a product that will stick to the concrete as you describe. Thanks again. Rick

Answer
Hi again Rick, non shrink Grout is used under columns after they have been set.  It can be found in most home improvement or lumber stores.  It has a fine texture and is self leveling when mixed to a wet consistency..If you are worried about "sticking" you can use a latex bonding agent (a milky liquid found in the masonry department of Lowe's or Home Depot) This can be painted on the surfaces of where you want the grout to stick and can also be used for mixing the grout as a water substitute.  Follow the manufacturer's instructions and you will be fine.   I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com