Reader Question: How to Repair Cracked Grout

As you may know, we met and dreamed up the idea for this brilliant blog while  working at the same nonprofit organization.  So perhaps it is no surprise that some of our co-workers are readers and like to talk to us about the projects that they see on the blog.  We’re basically celebrities. But as much as we love talking about us, our favorite is when they ask us questions about their own DIY or decorating projects — it means we’ve somehow tricked them into thinking we’re experts at this (check out the advice that we gave our friend, Stephanie, on decorating her patio).

So we were recently thrilled when a totally boring business meeting was interrupted with a conversation about grout.  Our co-worker, who we will anonymize for her protection as “Mecky,” had the following question:

Hi Team Plaster and Disaster,

I need your advice! It looks like the grouting in our 1.5 year old bathroom needs to be redone. There are cracks in it along the corners and my mother is convinced that black mold is imminent. It would be a stretch to call me handy but it seems like this should be something a novice could take on. What do you think?

– “Mecky”

At our desperate insistence polite request, she also provided these pictures of the issue:

Thanks for your question, “Mecky!”

Based on what we’ve read, this seems like a project that a regular homeowner could do.  We would both be comfortable taking on this project in our own homes, and neither of us have much experience with tile or grout.  But the thing we always consider is whether it is worth our time.  Depending on how extensive the cracks are, this could be a very time consuming project.  It really depends on how you would like to spend your Saturday.

If you are crazy like us and think this sounds like a great way to spend a Saturday, here what we’ve learned about how to fix this yourself:

How to Repair Cracked Grout

The first step is to remove the old grout surrounding the cracks.  It’s a bummer, but very important. According to “the floor elf” (an elf who apparently writes a blog about tiling floors), the new grout or other filler won’t be able to bind to the old grout so it is important to clear it entirely from the sides of the tile, and at least 2/3 of the way down each affected tile, so that it has enough area to form a good bond.

They sell tools specifically for this called “grout saws,” like this one from Amazon (affiliate link – read our policies), which was just $15 when we looked.

You can also use a dremel, which is probably not worth buying just for this project, but is a very handy tool to have around as a homeowner.  Sage has this dremel (affiliate link – read our policies) and likes it quite a bit.

Once all the grout is cleared, wipe it down with a damp cloth to remove all of the debris and dust. Then, you are ready to fill it with a new material!

The Great Grout Vs. Caulk Debate

Our extensive internet research has revealed two camps of thought on this: the grouters vs. the caulkers.  But the one to choose really depends on what you think caused the problem.

If you think that the cracks were caused by incorrect grouting to begin with, then you might want to try to fill it with new grout.  (You can tell it may have been done poorly if the cracks formed very soon after the tiling was originally done, showing that the grout may have been mixed incorrectly, etc.)  The benefits of using grout are that it will be a lot easier to match the color and texture of your current grout, and that if it works, it will be a permanent solution to the issue.  The major drawback is that if the cracks were formed by a structural problem, the new grout will just crack again and you’ll be right back where you started from.

If you think grout is the solution, we found this article on SFGate to be a pretty good tutorial for that process. Besides getting the right color, the other big thing to know when you pick a grout is whether you need sanded or nonsanded. Nonsanded is used in spaces smaller than 1/8 inches and sanded in spaces larger than that, so based on your pictures you would probably need nonsanded.

On the other hand, the floor elf is a major proponent of using caulk instead.  (Guys, we LIKE this elf. He is hilarious. He is also very authoritative for an elf, and we’ve based at least half this post on his advice.)

Caulking seems to be recommended if the cracks are caused by a shifting in the foundation or the joints where they are applied.  Grout has no give-and-take and so will crack if there is movement.  This is most likely to happen at corners and the edges between wall and ceiling or floor, so from your pictures it seems like this may be the issue for you.  Caulk has flex, and so can maintain its seal through these shifts.  However, it will be trickier to match the color and texture to your current grout, so you’ll have to live with a more mismatched look.  Also, caulk isn’t a permanent solution, so you might find yourself scraping it out and replacing it every few years.

If you do go the caulking way, we encourage you to read the floor elf’s post on the subject (he is also very responsive in the comments if you have detailed questions).   This tutorial by the Family Handyman and this one on Houzz are also good quick overviews on the process — they recommend using a special caulk called “ceramic tile caulk.” This special kind of caulk — which you should be able to find at most home improvement stores — comes in sanded and nonsanded variations just like grout, and again you’ll probably want nonsanded given that the spaces between your tiles are less than 1/8 inches.

We hope that was helpful, “Mecky!”  Thanks for your great question.  We learned a lot about grout today are definitely trustworthy experts.  We’d love to hear what you decide to do, and how it works!

 

(Sharing at Tip Me Tuesday, Think and Make Thursday, and Your Turn to Shine Link Party)