Grout and caulk are both common household sealants used for slightly different purposes. Understanding when to use grout versus caulk can ensure you complete your home improvement projects successfully.
What is Grout?
Grout is a cement-based sealant used to fill in the spaces between tiles. It creates a waterproof barrier and binds the tiles together to form a cohesive surface.
The main purposes of grout are:
- To fill in the gaps between tiles, leaving a smooth finished surface.
- To prevent moisture from seeping underneath the tiles and causing damage.
- To secure the tiles in place and prevent them from shifting.
There are several different types of grout available:
Sanded Grout
Sanded grout contains fine sand particles and is best for wider grout lines that are 1/8 inch or larger. The sand gives it durability and helps prevent cracking. Sanded grout is often used for floors due to its strength.
Unsanded Grout
Unsanded grout has a smooth consistency without sand. It’s suited for narrow grout lines under 1/8 inch, such as wall tiles or mosaics. Unsanded grout resists shrinking or cracking.
Epoxy Grout
Epoxy grout is an extremely durable chemical-based grout. It has an acrylic resin that makes it more stain-resistant than other grout options. Epoxy grout doesn’t require sealing. It provides a strong, waterproof bond.
Specialty Grout
There are also specialty grout options available, such as urethane grout that contains silicone. These types of grout are often stain-proof and waterproof. They’re ideal for countertops and floors in high-traffic areas.
When selecting grout, consider the type of tile, width of the joints, and location. The manufacturer’s recommendations can also help determine the best grout for the job.
What is Caulk?
Caulk is a flexible sealant used to fill in cracks, gaps, and joints where two different building materials meet. The main purposes of caulking are:
- To seal areas not covered by grout, such as corners, changes in plane, and joints between the tub and tile.
- To allow for expansion and contraction between materials.
- To provide waterproofing by sealing joints vulnerable to moisture damage.
There are several types of caulk for various applications:
Silicone Caulk
Silicone caulk has silicone polymers that make it extremely flexible and waterproof. It can withstand temperature changes and moisture without cracking or shrinking. Silicone works well in bathrooms and kitchens.
Latex Caulk
Latex caulk contains latex polymer resins. It remains slightly flexible when dry. Latex caulk is easy to apply, clean up, and tool into a smooth finish. It’s ideal for minor interior jobs.
Acrylic Latex Caulk
Acrylic latex caulk has acrylic added to the latex base. It tends to be more durable and flexible than pure latex. Acrylic latex works well for windows, doors, siding, trim, and exteriors.
Polyurethane Caulk
Polyurethane caulk is highly elastic and durable. It offers excellent adhesion power and long-lasting flexibility. Polyurethane is often used for sealing roofing, gutters, and outdoor projects.
When selecting caulk, consider the location and materials you’re sealing. Choose a caulk that can adhere well and remain waterproof.
Key Differences Between Grout and Caulk
While grout and caulk are both sealing agents, there are some key differences:
Purpose
- Grout fills the gaps between tiles and binds them together into one unified surface.
- Caulk seals joints and seams between dissimilar materials.
Flexibility
- Grout is rigid and provides a hard connection between tiles.
- Caulk is flexible and allows movement between materials.
Composition
- Grout is cement-based, while caulk is latex, silicone, or acrylic-based.
Performance
- Grout resists compression but can crack.
- Caulk withstands expansion and contraction without cracking.
Appearance
- Grout has a gritty, sandy appearance.
- Caulk has a smooth, consistent finish.
Durability
- Grout lasts longer under direct traffic.
- Caulk adheres better to different surfaces.
Application
- Grout is applied between tile joints.
- Caulk is applied where tile meets another material.
When to Use Grout
Grout should be used:
- In the joints between all tile surfaces, such as floors, walls, countertops, and backsplashes.
- To fill gaps 1/8 inch and larger between tiles.
- Anywhere tile needs to be secured tightly together without flexion.
- For high-traffic flooring and areas needing durability underfoot.
- In dry areas not exposed to standing water or dampness.
- Where a sandy finish between tile is desired.
Choose the type of grout based on the tile material, joint width, and location following manufacturer guidelines. Sanded grout works for floor tile joints. Unsanded grout suits wall tiles with thin grout lines.
Be sure to apply grout once tile layout is firm and level. Clean any joints or gaps before grouting. Follow instructions for cure time and avoiding surface contact until grout is fully set.
When to Use Caulk
Caulk should be used:
- Along countertops, edges, corners, and transitions wherever tile meets another material.
- Where tile borders sinks, tubs, plumbing fixtures, cabinets, or appliances.
- In areas of tile not supported by backer board, such as above a bathtub.
- For vertical joints, changes in plane, and fitments in tile installation.
- Around perimeter edges of a tile flooring area.
- For flexible waterproof sealing between tile and other surfaces.
- Inexpansion joints that need to move and flex over time.
- For moisture-prone areas like around tubs and showers.
Choose caulk over grout for joints under 1/8 inch. Use 100% silicone caulk in wet areas like bathrooms and kitchens for water resistance. Acrylic latex works for indoor/outdoor areas exposed to the elements.
Apply caulk after grouting is fully complete. Tool the caulk into a smooth, consistent bead. Wipe away any excess caulk for a neat appearance.
Tips for Using Grout and Caulk
When using grout and caulk for tile projects, keep these tips in mind:
- Read all manufacturer instructions for proper setup, application, and curing.
- Plan tile layout with grout lines in mind. Standard joints for floor tile are 1/8-1/4 inch. Wall tiles can have 1/16-1/8 inch grout lines.
- Choose grout colors to complement or match the tile. Contrasting grout can also be used for effect.
- Use sanded grout for floor tile wider than 1/8 inch. Use unsanded grout for wall grout lines under 1/8 inch.
- Make sure grout joints are uniform in width and depth for consistent filling.
- Clean excess grout off tile before it dries using a damp sponge in diagonal motions.
- Don’t allow grout to fully dry on the tile surface or it will be hard to remove.
- Apply caulk in all corners, edges, and gaps where tile meets another material.
- Tool caulk into a smooth, consistent bead using a damp finger. Wipe away excess.
- Allow caulk to fully cure based on manufacturer directions before exposing to water.
- Use 100% silicone caulk anywhere moisture is a concern, like around tubs and sinks.
- Re-apply grout or caulk as needed over time to maintain waterproof seals.
Grout vs Caulk: Frequently Asked Questions
Should I use grout or caulk around a bathtub?
Use 100% silicone caulk around bathtubs. The caulk remains flexible to prevent cracking or water leaks. Grout will crack in areas that move or flex over time.
When should I use epoxy grout?
Epoxy grout is great for countertops, floors, and walls in bathrooms, kitchens, and other high-moisture areas. The chemical formulation makes it highly water-resistant.
How do I apply caulk for a smooth finish?
Apply caulk in a continuous smooth bead. Use a damp finger or tool to smooth it out evenly. Avoid any gaps. Wipe away excess caulk with a clean rag before it dries.
Can I use sanded grout for wall tiles?
Sanded grout can be used for wall tiles if the grout lines are 1/8 inch or wider. For narrow wall tile joints under 1/8 inch, use unsanded grout.
Should tile corners have caulk or grout?
Interior and exterior tile corners should be caulked, not grouted. The caulk allows for slight movement and expansion to prevent cracking.
How soon can I get tile wet after grouting?
Follow manufacturer cure times, but you’ll typically need to wait 24-48 hours before exposing grout to water. Ensure grout is fully set before use.
How do I clean dried grout off my tiles?
Use a grout haze remover product or mix baking soda with water into a spreadable paste. Let it sit for 5 minutes before scrubbing and rinsing. Be careful not to scratch tiles.
When should I re-caulk areas in my home?
Inspect caulk annually and re-apply anywhere you see cracks, inconsistent widths, gaps, or signs of damage. Shower and sink areas may need re-caulking most frequently.
Can I grout over existing cracked grout?
Remove all old grout first in the joint before re-applying fresh grout. Grout doesn’t adhere well if applied over residue of existing grout.
Conclusion
Knowing when to use grout vs. caulk for your tile project can ensure successful results and a professional finished look. Follow these simple guidelines:
- Use grout to fill in the joints between tiles. Choose sanded or unsanded grout based on the tile location and joint width.
- Use caulk anywhere tile meets another material, such as around edges, corners, fixtures, and changes in plane.
- Choose silicone, latex, or acrylic caulk based on the project needs.
- Allow proper cure time for grout and caulk to fully set and seal.
- Maintain the grout and caulk over time with re-application as needed.
Properly using grout and caulk together results in a waterproof surface designed to last. Paying attention to the details makes installing tile much easier. Carefully review manufacturer instructions and use the appropriate product for each application.