Re Grouting Glass Block Tiles. You Can Do It!

by ThriftDee
2 Materials
4 Hours
You can repair and replace the grout in your glass tile all by yourself! If you can ice a cake you can do it!
We had our bathroom completely renovated when we bought our house. The cabinets and floors could be salvaged but the shower and jacuzzi tub HAD TO GO. Just like every other project once the fixtures look nice you realize other things that need to be spruced up.
Like this crumbling grout for example. The contractor said that he would do it but he thought I could do it myself to save him time and save me MONEY! The first thing you need to do is remove all of the crumbling grout with a mallet and a chisel or screwdriver. Be careful and do not unleash your inner Chip Gaines!
Once all of the crumbling grout is removed make sure to vacuum up all of the loose sand and dirt. Wipe everything down with a 1:4 mixture of white vinegar and water. It has to be completely dry so wait at least 48 hours before you start re-grouting. I live in AZ where it is 247 degrees so things dry pretty fast.
Gather up your supplies. You will need sanded grout, a plastic bucket to mix it in, a stir stick, rubber or latex gloves, a masonry sponge, water and an offset spatula or grout trowel.
Read the directions on the sanded grout bag first. REALLY. Then mix up the grout using just as much water as you need. You can always add a few drops more. You are looking for the consistency of creamy peanut butter.
Using an offset spatula or grout trowel you will be pushing the grout into the space. By putting the grout onto the BACK of the spatula it is easier to manage without it falling off of the trowel. The finished grout needs to be flush with the glass brick. Then using the just damp sponge, you will wipe away any excess grout. Some grout haze was left on the brick but I waited 24 hours to wipe that away with just water.
Watch my HOMETALK LIVE VIDEO for step by step instructions with visuals!! You can do it!!
You can see the finished grout on the right just before I cleaned off the haze. I only did a third of the window so I could finish it LIVE.
This is a closeup of the finished grout. Pretty good for an ameteur!!
Suggested materials:
  • Sanded Grout   (Home Depot)
  • Offset trowel   (Ace Hardware)
Want more details about this and other DIY projects? Check out my blog post!
Frequently asked questions
Have a question about this project?
3 of 4 questions
  • Chris Ann Hanousek Chris Ann Hanousek on Dec 04, 2017

    Thanks for the instructions. Please explain how sand grout differs from regular grout. i think they put that in my bathroom and on my tile table. Does the sand crumble off ehen ypu clean it? How do you clean it? Can/should you seal sand grout?

  • Queenbee Queenbee on Dec 27, 2017

    I love glass block and have it as a window in the bathroom but during the winter, I live in the Midwest where it gets below zero temps, there is cold air coming off the glass blocks. Is that normal, do they make glass blocks that have an insulation factor?

  • Richard Johnson Richard Johnson on May 31, 2018

    Can urethane grout be used over traditional grout for this type of repair? I'd like to repair my glass block shower wall, but it looks to have traditional grout. I'm thinking of using urethane grout, since it would be easier to use and probably have a little flexibility, seal better, etc.

Join the conversation
3 of 10 comments
  • Jacquelyne May Jacquelyne May on Dec 04, 2017

    My house was built in 1939.

    The all tile bathroom grout stays clean and white with minimal care.

    The places where I have had to re-grout need re-grouting again every few years.

    What's with that???

    I have tried every different brand I can find.

    • Sherri M. Sherri M. on Dec 20, 2017
      On a tile floor, I'd make sure to use a regular grout sealer liquid. Good luck ✌
  • Pam Davis Pam Davis on Dec 05, 2017

    Very well done. It looks great! 🤗