Sanded vs. Unsanded Caulk: Which One Is Right For Your Tiling Job?

Kenneth Wilson

If you're thinking of doing a kitchen backsplash or a bathroom tiling project– you may have to deal with the dilemma of using sanded or unsanded caulk. We talk to homeowners daily, and we often hear related questions such as: What exactly is the difference between the two? How do you determine the right caulk for your tiling job?

For starters, sanded caulk is composed of either acrylic, latex, or silicone with sand for added texture and bulkiness, whereas unsanded caulk lacks it. (Related: 6 Simple Steps To Remove Silicone Caulk From Tile) Unsanded caulk is smoother and preferable for joints less than ⅛ inches between the two. Sanded caulk is commonly used for larger tile joints.

Many homeowners remain uncertain about the variations of the two caulk types. Now, let's discuss the differences in detail to decide for yourself which is the right caulk type to use for your project.

Sanded vs. Unsanded Caulk: The Major Differences

True to its name, sanded caulk has the extra ingredient of sand. Since unsanded caulk tends to shrink after application, the presence of sand can effectively prevent this from happening.

Sanded caulk is mainly used to fill in gaps where shrinking caulk (unsanded) may result in poor adhesion. It may also be matched with the look of the grout. Sanded caulk may also be unable to resist mold growth, so it's not suitable for bathrooms and kitchens.

In contrast, unsanded caulk proves to be more flexible and has higher mold resistance. It is also available in several different colors to complement your decor. Refer to the table below for a quick rundown of sanded and unsanded caulk differences.

Sanded Caulk

Unsanded Caulk

Bulkier and suitable for large tile joints (more than ⅛ inches)

Fine texture. Ideal for joints less than ⅛ inches

Creates stronger joints with strong sand-bonds

Less brittle and lighter joints. It lasts longer, even in water

Not a flexible tile-joint sealing material

Adjustable and suitable for vertical tiling

May encourage mold and mildew growth

Waterproof and mold-resistant

Best paired with sanded grout

Best paired with unsanded grout

Properties of Sanded vs. Unsanded Caulk

Let’s discuss the different properties of sanded and unsanded caulk.

  • Mold-resistance: Unsanded caulk is highly mold-resistant, whereas sanded caulk may be prone to mold/mildew growth. It is also notorious for foul odor and possible health risks.
  • Flexibility: This product has less flexibility than unsanded caulk with sand in the sanded caulk. Expect that your project may be more prone to cracks.
  • Areas of Use: You can use unsanded caulk to fill in the joints of perpendicular surfaces, as long as they are not too wide. In contrast, sanded caulk is more suitable for wider joints (as long as they’re not located close to the bathroom or the sink).
  • Durability: Sand material is noted to make the caulk much more durable, resilient, and robust. As such, sanded caulk is considerably more durable than its unsanded counterpart. Unsanded caulk material tends to shrink over time– pulling away from the tiles and gradually breaking up.
  • Longevity: Most contractors opt for sanded caulk in interior flooring projects, mainly due to its longevity. Even with heavy foot traffic, it is known to last longer than unsanded caulk. This caulk type is also resistant to scratching, making your tiles stronger. On the other hand, unsanded caulk can be vulnerable to extreme cracking. Contractors usually avoid using unsanded caulk for residential flooring and tiling projects. Pro Tip: For your next tiling job, prioritize finding high-quality sanded caulk if you want more durability and resistance.
  • Vertical Prowess: In discussing sanded vs. unsanded caulk, you will need to know its vertical adhesiveness. Most likely, unsanded caulk is used to mount a shower or install vertical tiles. It is known to be highly rigid, as it doesn't contain any extra sand. Unsanded caulk can be quickly scattered across a vertical surface in a complete and even distribution.
  • Caulk Shrinkage on Vertical Surfaces: Unsanded caulk is known to shrink faster than sanded caulk, but this isn't a significant problem on a vertical surface. Little (to virtually no strain) is applied on vertical tiles. That said, the tiles are typically laid down close to each other– ensuring that the shrinkage won't affect the tile's longevity.
  • Preventing Tile Damage: The tile material is another factor to consider in deciding whether to use sanded caulk or its unsanded counterpart. A word of caution: the hard sand content in sanded caulk may be harmful on granite, marble, limestone, and other tile materials. Think of sanded caulk as sandpaper. It is often harder and coarser than standard tiles, damaging its quality and surface. For soft and smooth tiles, it's better to use unsanded caulk. Flooring contractors in the country use epoxy-based unsanded caulk for most tiling projects because of its shiny and polished look.
  • The Size of the Joints: Sanded caulk is not recommended for joints less than ⅛ inches, as you may end up dealing with problems in the long run. For small joints, use unsanded caulk instead as it's more suitable for such projects. The sanded material also makes the caulk highly durable, making it difficult to squeeze into tight holes and spaces.
  • Pinhole Effect: The pinhole effect is another problem you can expect in using sanded caulk for tiny joints. Contractors always use more water for the foundation to quickly spread the caulk– though it may also create pinholes in the process. It will undoubtedly destroy the result of your tiling project. You will most likely need to refill these holes to prevent future issues.

Which Caulk is Better: Sanded or Unsanded?

Technically, there is no correct answer to this question. Whether sanded or unsanded caulk is better will depend on the joints' thickness and location. It's more suitable to use sanded caulk for large joints with sanded grout. Meanwhile, unsanded caulk is better for narrow joints between tiles and counters.

Homeowners with a tight budget can choose sanded caulk, as the sand makes caulk bulkier to fill any spaces, so you're less likely to spend on more caulk products.  For joints in the shower and kitchen, it's best to use unsanded caulk as it can handle moisture and temperature fluctuations. As a result, it minimizes the chances of cracks.

Now that you've grasped the significant differences between sanded and unsanded caulk, we hope that you can now make the best choice for your home improvement project! Always consider the task requirements, area of installation, size of joints, and expected foot traffic if you want to make an informed decision.

Frequently Asked Questions (FAQs)

Does sanded caulk need to be sealed?

Sanded caulk does not need to be sealed. Water-resistant properties of silicone, latex, or acrylic caulk do not change by adding sand to caulk. Although, using grout will require you to seal it right after application to avoid possible water damage.

How long does sanded caulk take to cure?

Twenty-four hours is the minimum time before sanded caulk can be exposed to any water. However, it may take longer to cure, depending on the thickness of the application and room temperature.

Can I paint caulk?

Yes, but some caulks can't be painted. Make sure to read the tube stating that it is paintable before purchasing it.

Can I sand caulk?

Sanding caulk may degrade the surface, and while this isn't as noticeable on sanded caulk, the look of your finished job can still be ruined.

Kenneth Wilson
January 18, 2022
Contractor Tips, Interior

Kenneth Wilson

Retired contractor. Currently residing in Southwest Florida. Now in semi-retirement, I write and manage this blog focused on helping home owners make savvy decisions when it comes to finding contractors and getting their projects done. I also operate remodeling design service for homeowners.

Ask The Author Your Question In The Comments!

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

More From This Author

9 of the Best Ring Security Cameras: Home Security 101
Where You Should Place Security Cameras Around Your Home: Best Locations
How Long Do SimpliSafe Camera Batteries Last?
SimpliSafe vs. Ring: Which Home Security System is Best Suited for Your Needs?
The Best Plug-in Outdoor Security Lights to Keep Your Home Safe
Everything You Need to Know About Residential Laser Grid Security Systems