How do I redo the grout on the Granite Countertop and the Backsplash?

Usually, that seam is filled with a colour-matched latex caulking vs. grout. Have you caulked before?

Here's a how to: https://www.washingtonpost.com/news/where-we-live/wp/2015/12/15/how-to-fix-cracked-grout-on-new-granite-counter/

Is it a solid granite counter or is it tile? I would look into taking out all of the grout that's loose and replacing it with a latex based caulk.

here is some info but I think I would call the installers and ask them to redo it or what they use

https://www.katelotile.com/guides-tools-post/why-is-the-grout-between-my-counter-and-backsplash-cracking/

https://www.houzz.com/discussions/2306071/caulk-or-grout-between-granite-counter-and-travertine-backsplash

Is in grouting or caulking?

Posting a picture of the area in question would help illustrate the problem.

The corner seam between the counter and backsplash should be caulked not grout. You can get colored caulk at Home Depot, Lowes, or Menards. You will need a caulking gun too.

Buy a grout remover tool, then take out the crumbling grout. But some unsanded grout and follow the directions for re-grouting. Ask at Home Depot, Lowes or Floor and Decor. They will point you in the right direction.

I'd use caulk to replace it, caulk is flexible.

We used a manual tool and it was taking forever so we bought this one https://www.harborfreight.com/variable-speed-oscillating-multi-tool-63113.html?cid=paid_google%7C%7C%7C63113&utm_source=google&utm_medium=cpc&utm_campaign=&utm_content=&gclid=CjwKCAjwg4-EBhBwEiwAzYAlsmaL26kSW2URFesr9oMfJlDCYlN1R5zGgiR5L2LOaSJoCcWeTyS7dRoCwMkQAvD_BwE

sounds good was thinking about that

We just used Prisma grout in our kitchen backsplash. We went with that because it has the sealer already in it. We finished it about 2 weeks ago. I hope it holds up well.

Hi betty, hope this video helps you out,

https://www.youtube.com/watch?v=XzxbUrlPKh8

Hi Betty, it sounds like the grout wasn't mixed properly. Probably too little water in the mixture. Your best bet would be to scrape out the grout and completely replace it. You can use a grout rake or remover to make things easier. Once the joints are clean, apply the correctly-mixed grout.

You could go large DIY store and purchase a flexible sealing strip on a roll, or talk to the staff there about your problem and get a bit more help as to your options acording to your abilities. Hope that helps.

https://www.youtube.com/watch?v=ZMAc9FlshnM

Remove the grout from all the areas and then either caulk or re-grout insuring it is the color and mixed correctly so it does not pop out when dry.

I had that problem a long time ago. I took the grout out with a grout remover tool and then replaced it. I used blue tape so I would not get it all over the granite. Then when dry I resealed it.

https://www.youtube.com/watch?v=AxrR0KobYvs

Hi Betty, here's a great solution for you, replace it with caulking,

https://www.youtube.com/watch?v=AxrR0KobYvs