Rusty Bathroom Tile Grout: Clean or Replace?

LESLIE: Bill in Texas has a question about rusty grout in a bathroom project. What’s going on?

BILL: Yes, ma’am. A couple of years ago, I put in a tile shower. I’d removed a fiberglass shower and I put in a tile shower. And the problem is – you know how you put the rubber barrier up like 42 or 48 inches? I put that up but I’m guessing that I should have used stainless-steel screws. Because in two spots, you can kind of detect a rust color kind of seeping through the grout? And I’m wondering if I should remove the grout and maybe try – they have that epoxy-based grout, if I should do that or if there’s – when I remove the grout, if there’s a product I should apply to kind of neutralize the rust.
Basically, that’s what’s going on. I’ve just – I’m decently handy, so I know I can remove the grout and everything but I’m just wondering what steps I should take to prevent the rust from coming back.

TOM: Well, the sand-based grout certainly is going to allow any rust stains to kind of permeate right through. Epoxy grout probably would not. That might be the simplest solution if it’s just minor surface rust. It’s a little bit late now to pull tile off and start changing fasteners, so I think that probably makes the most sense, Bill – would be just to remove the old grout with a grout saw and then regrout it with epoxy-based grout which, by the way, is a little harder to work with. So make sure you take your time, maybe practice off those bathroom walls before you apply it to it. But I think that’s probably the best solution in the short term.

BILL: Now, the – for automotive, they have POR-15 and different products to neutralize the rust. Is there anything like that that you – would it be worthwhile to even try to attempt that or is it not worth my time?

TOM: I’m not familiar with those products but my concern would be that, you know, if you got one, it’ll probably open up somewhere else along the way, so it’s kind of like you’re chasing a ghost after a while.

BILL: OK. So maybe try the epoxy grout and cross my fingers?

TOM: I would say so. I think there’s a pretty good chance it’s going to work out, Bill, OK?

BILL: OK. Thank you so much.