Caulk is something you will find in every bathroom, regardless of its style or size. It’s also something millions of homeowners use each year to fix or fill old gaps in their tiles.
Wondering if you can caulk over grout? Well, you might be surprised by the answer.
In this guide, we will talk about what you should use to repair grout and what happens if you use caulk in its place. We’ve also put together a list of tips that can help make this type of maintenance a thing of the past.
The Difference Between Caulk and Grout
Before discussing if you can caulk over grout, it’s a good idea to understand a little more about the substances themselves.
Grout is a mixture used with materials like stone, glass, and tile. It fills in the gaps between these and provides a strong bond.
While there are several types of grout, residential grouts fall into one of three categories:
- Sanded Grout – Sanded grout is made from a mixture of cement, sand, and water. It’s porous, so it’s not waterproof, which means a sealer is required.
- Unsanded Grout – This is a variant of sanded grout but with a smoother texture because there is no sand. It can provide a unique look but isn’t as strong as sanded grout.
- Epoxy Grout – When you need grout that’s resistant to stains and doesn’t need to be sealed, epoxy-based grout is the best choice. It’s great in showers — and kitchens — for those reasons.
What About Caulk?
Whereas grout’s only used in certain areas, you can find silicone or acrylic caulk in almost every room of your home. You might not see it, but this popular filler is found around baseboards, doors, windows, and bathrooms.
Both acrylic and silicone caulk can bond to a wide variety of surfaces, including glass, plastic, metal, and ceramic. That makes it an excellent choice for bathrooms — especially around the tub or shower surround.
Caulk is waterproof, and it’s great for filling gaps.
That said, mixing grout and caulk together isn’t necessarily a good idea for various reasons.
Can You Caulk Over Grout?
So, can you silicone or acrylic caulk over grout? The answer is yes, but whether you actually should is an entirely different story.
First, caulking over grout will never be aesthetically pleasing. But that could be the least of your worries, depending on the location.
Latex and silicone caulk will adhere to grout when properly cleaned, although that bond won’t last. The caulk will begin to fail and peel away from the grout over time.
And, when this happens, mold and mildew can find a foothold and begin to grow in the small spaces. It can actually grow between the grout and caulk, completely undetected before spreading in your bathroom.
If water or moisture does find its way beneath your tile or stone, you’ll end up with an expensive problem on your hands.
How Do I Repair or Remove Old Grout?
Now that you know using acrylic latex or silicone caulk over grout is a bad idea, it’s time to talk about how to fix any old grout in your home.
You’ll need a handful of tools, but this task is something that any homeowner can perform in less than a day.
You’ll also need rags, sponges, and possibly a shop vacuum for cleanup when removing and replacing grout.
Grout comes in a variety of colors and in two forms — pre-mixed and bagged grout. For smaller jobs, you can pick up a grout repair kit or tub of grout. We prefer the latter and a pack of spreaders as it gives you more to work with for a similar price.
You can purchase products like SimpleGrout online or from your local hardware store. The same goes for grout sealant or silicone caulk, which you may need depending on the situation.
You’ll also need to seal the fresh grout once the job is complete.
- Grout saw or oscillating tool
- Safety glasses
- White vinegar
- Shop vacuum (optional)
- Caulk gun/Caulk (optional)
Removing and Replacing Grout
Step 1: Remove Old Grout
The first step is to remove damaged grout with your saw or oscillating tools. The important thing is to go slow regardless of what you use — if you attempt to pry debris from grout lines, you can damage or pop the tile loose.
You don’t need to remove all of the old grout — only damaged portions along with any loose debris. New grout just needs a clean, rough surface to adhere to when being applied.
This excellent video will give you a good idea of what to expect when using a smaller grout saw. An oscillating tool is faster but doesn’t provide as much control.
Step 2. Clean the Area
Now it’s time to clean the area. To do this, use a 1:1 mixture of vinegar and water to remove any dust or debris from the existing grout site.
With vertical surfaces, you may only need to wipe them down, but a shop vacuum or small paintbrush may also come in handy to clean out the grout lines.
Ensure the area is completely dry and clean before filling in the gaps or applying new grout over old joints. Check the directions on the grout you’ll use and prep the area accordingly.
Step 3: Apply New Grout
When using tube-based grout, you simply need to fill the grout lines or gaps by squeezing the tube.
The process is similar for grout that needs to be mixed or that comes in a tub. When properly mixed, you simply take grout with a spreader and work it into the gaps.
Step 4: Clean Up the Grout Lines
For this, you’ll need to wait for the grout to set (but not dry), which may take between 20 to 30 minutes depending on the product.
Once ready, remove any excess grout with a damp sponge or rag. You can then use a grout tool or a wet finger to smooth down the seam a bit below the tile to match the old grout lines.
Check the manufacturer’s directions on the tile grout you’ve used for dry times. When you are sure the fresh grout is completely dry, it’s time to apply a sealant to make it waterproof.
Step 5: Apply Sealer
Ensure the area is completely clean and without grout haze before you begin.
There are a number of products available to seal grouted tile, but something in a spray bottle should suffice unless you are refinishing a large area.
When complete, wait the allotted time before getting the area wet.
Whether or not you should caulk over grout should be clear after reading our guide.
While it is acceptable in certain applications, it’s a temporary solution to a larger issue.
You can expect grout to last around 10 to 15 years in most cases, though how long it stays intact depends on how well it was applied and the type of grout used.
Is there a safe way to use silicone caulk over grout?
Trying to blend any type of caulk with grout will never give you a “clean” match and will eventually peel away. That said, it can be used as a temporary solution in dry or damp areas until re-grouted.
Can you use caulk over existing caulk?
Yes, but the area will need to be prepped and the older latex or silicone caulk removed before applying the fresh caulk in any seam or gap.
Should I use sanded or unsanded grout?
While it’s a matter of appearance or necessity in some cases, always use sanded grout for joints larger than 1/8”.
What consistency do you need when mixing grout?
Grout should be thick enough to stay on the spreader used to fill in the gaps and joints. Plus, too much water can dilute the color.
A peanut butter-like consistency is the best for mixed grout.
Can you stain or change the color of grout for a better match?
There are ways to alter the shade, but the easiest method is through the use of a grout pen which adds a touch of color.