Charlie: Ryan from Pasadena writes to us. He says, “When I recently bought my home, I had five areas of my post-tension foundation where the cables were exposed. The home inspector says I need to clean and seal these exposed areas. Is this is a concern and what should I do about it?”
Tom: It is a concern and somebody needs to deal with it, whether the homeowner does or you hire somebody to do it. But they’re going to clean them up and maybe even spray a little paint on there. You don’t want them to rust to where the cables snap. Remember they’re under tension, or they’re supposed to be, at least. And there are companies that actually will come in and recable and fix these things after they’re broken.
In fact, I’ve talked to the people at Du-West, we were just talking about. And they were telling me there are companies still out there doing that. But it’s a problem with post-tension cables. And yeah, it needs to be cleaned up. You can use a little sandcrete and bonding agent, mix it together and put over the top of it, but they do need to be protected, and that’s a flaw in the whole post-tension system. Hopefully it won’t cause too much problems if one of them snaps, but you do need to address the issue.
Charlie: And how do you do it, Tom? Do you just clean them up and cover them over?
Tom: If you get a wire brush, you can wire brush them. You can clean them with a little vinegar and water, just get the rust off it, and if you take 50% bonding agent, which is like an Elmer’s glue … you can buy it at Home Depot for concrete … and 50% water, mix it up with some sandcrete. Unfortunately, you have to buy a bag, and I don’t think you’ll need a whole bag unless you have a bunch of them. But you buy a bag of that stuff, and it’s just cement with no aggregate. It’s just got sand in it and cement, and then you just trail over the top of it, and it’ll look like it’s been patched, but they always do, but it’s not going to be a problem and it’ll protect it.