Tile pros, please help. What should I do here

[Billbill84]

hi guys.
To start off, I have some 19yr old tile that has some grout issues in the bathroom and mud room, presumably from wet shoes/winter salt breaking down grout. Most areas look ok there's just a few eye sores. In the bathroom some grout lines are still smooth but kinda deep (see pics), so maybe that's how it was installed?

How do I go about repairing these spots or do I need to have the floor completely regrouted?? If it's just a few bad spots would it make more sense to just patch with a premixed matching grout? Has anyone made repairs with these kinds of grout crumbling? Thx

 

[Skeezix]

I certainly would try patching the spots if I could get something that will match in color. First I'd dig out the grout that's crumbling and clean the crack out, then fill it in with new grout. Certainly better than paying $$$ to have somebody re-grout the 19-year-old tiles and then having new crumbling areas.

 

[Billbill84]

I certainly would try patching the spots if I could get something that will match in color. First I'd dig out the grout that's crumbling and clean the crack out, then fill it in with new grout. Certainly better than paying $$$ to have somebody re-grout the 19-year-old tiles and then having new crumbling areas.

You're 100% right about that. I think I'll make a clean patch. Just need to figure out what's the best most durable materials to use here

 

[oldognewtrick]

I tried doing a skim coat over old grout before, looked good for a couple months. If I were going to repair grout joints again, I'd get a grinder or Oscillating Tool clean out the joints as deep as possible and then apply new grout.

 

[Billbill84]

I tried doing a skim coat over old grout before, looked good for a couple months. If I were going to repair grout joints again, I'd get a grinder or Oscillating Tool clean out the joints as deep as possible and then apply new grout.

Ok I'll try that