How to Mix Grout Like a Pro: Step-by-Step Guide

Grout Mixing Doesn’t Have to Be Complicated

Getting grout right isn’t just about looks, it affects how long your project lasts and how well it holds up. When mixed right, you get stronger bonds, a smoother texture, and a better-looking finish. Done wrong, and you’re left with cracking, uneven grout lines, or mismatched color.

For outdoor projects using cement-based grout, the MudMixer makes it easy. It’s a mortar mixer built for serious workloads, ideal for patios, walkways, retaining walls, and large stone or masonry installs, without the hassle of mixing buckets.

If you’re working on a backyard stone wall or grouting flagstone over a concrete pad, this walkthrough shows how to get better results, faster.

What Is Grout?

Grout is a thick, paste-like material used to fill gaps and secure surfaces like tile, stone, or masonry. It reinforces your installation, locks everything into place, and prevents water intrusion.

Here are the most common types of grout:

• Sanded grout: Contains fine sand, best for wider grout lines (over 1/8 inch).

• Unsanded grout: Smooth and best for narrow joints under 1/8 inch.

• Epoxy grout: A chemical-based option with high resistance to stains and moisture.

• Cementitious grout: The most common, typically made from dry powder, Portland cement, sand, and additives.

No matter which grout you use, mixing it properly is the key to a long-lasting, professional finish.

Where Is Grout Used? Common Outdoor Applications

Grout is used to fill gaps, bind materials, and finish joints in a variety of outdoor projects:

Exterior Tile Installation

• Holds outdoor tiles in place on concrete pads or steps

• Prevents moisture from penetrating underneath

Stonework

• Binds and stabilizes natural stone in patios, walkways, and walls

• Helps shape uneven stones into a clean layout

• Adds visual uniformity to uneven materials

Masonry Projects

• Seals joints in brick and block walls

• Used with mortar for surface finishing and extra reinforcement

• Improves surface appearance and weather resistance

What You’ll Need to Get the Job Done

Item	Purpose
MudMixer	Continuous and consistent grout mixing
Grout mix	Choose sanded or unsanded based on joint width
Water	Mixing element; varies by manufacturer
Bucket	For manual measurements or catching overflow
Trowel & float	For spreading and smoothing grout
Sponge & water	Cleanup post-application

Step-by-Step: How to Mix Grout with the MudMixer

1. Set Up Your Workspace

Choose a clear, level area with easy access to a water source. Gather all your materials and wear protective gear like gloves, safety glasses, and work boots if needed.

2. Load the MudMixer

Use the built-in bag opener to slice open your grout powder bags. Pour the dry grout mix into the hopper. The 35-inch height means no awkward lifting or straining.

3. Adjust the Water Dial

Start with the water-to-powder ratio recommended on your grout packaging. Use the MudMixer’s dial to fine-tune until your mix reaches the right thickness. For most tile grout applications, aim for a peanut butter-like texture—thick but spreadable.

4. Start the Mix

Power on the mixer.  The auger infuses water into the grout as it moves, creating a smooth grout mixture. The 330° pivot chute lets you pour directly into your work zone, avoiding buckets and back-and-forth trips.

5. Test and Fine-Tune

Check the mix early on. If it looks too dry or clumpy, bump the water dial slightly. If it’s too runny, reduce water input. You want smooth, spreadable grout with no dry clumps or air bubbles.

What Does a Good Grout Mix Look Like?

Visual cues are just as important as ratios. Here’s what to look for once the MudMixer starts doing its job:

• Well-mixed grout: Smooth, thick, and slightly sticky. It holds its shape on a float and spreads cleanly into grout lines without slumping.

• Too dry: Grainy texture, crumbly when spread, and may leave gaps or fail to bond well.

• Too wet: Pours off the float, settles unevenly in grout lines, and may cause uneven color or shrinkage as it dries.

Tip: Always test a small amount on a trial area or scrap material before applying to the full surface.

Can You Grout Over Grout?

Yes, but it only works if the existing grout is in good condition; clean, solid, and not flaking. Use a grout knife to lightly etch or sand down the old surface so the new grout mix can bond. Avoid applying over loose, dirty grout or damaged areas.

How Long Does Grout Take to Dry?

Grout usually takes 24 to 72 hours to dry, depending on humidity, temperature, and the type of grout used. Avoid stepping on or cleaning the tiled area during this time.

How Long Does Grout Take to Cure?

Curing takes longer than drying and gives grout its full strength. Here’s how long common grout types take:

Grout Type	Cure Time
Cement-based	72 hours
Epoxy grout	24 hours
Quick-set	~4 hours

Pro Tips for Best Results

1. Use small batch mixing for repairs or touch-ups, but go continuous for large areas.

2. Don’t overwater—it can lead to a weak, grainy texture.

3. Always check the label for mixing instructions and water ratios.

4. Keep temperatures between 50°F and 100°F during application and drying.

5. Clean tools and wipe excess grout off the tile surface within 15–30 minutes to maintain original color.

How to Dispose of Leftover Grout and Rinse Water

Proper cleanup matters just as much as the pour. The MudMixer includes a built-in hose attachment, making it easy to flush out any leftover grout mixture before it hardens. To dispose of rinse water, avoid pouring it down drains, especially if it contains solids. Instead, direct it over a gravel or dirt area away from stormwater systems, where sediment can safely settle. Let any leftover grout dry completely in a bucket or tray before tossing it with regular construction debris. Quick cleanup not only protects your tools, it keeps your next mix running smoothly.

For more tips on cleaning your MudMixer and maintaining its performance, read our full guide here.

Why Mix Grout with the MudMixer?

The MudMixer helps you mix grout quickly, cleanly, and with less effort. Built tough and backed by a 2-year warranty, it’s the smarter way to mix.

Feature	Benefit
Adjustable water control	Precise consistency every time
Electric motor	No manual labor needed
Continuous mixing	Say goodbye to batch delays
Pivot system	Targeted delivery to work area
Durable build	Handles grout, mortar, stucco, and more

Grout Mixing Done Right

If you’re looking to get professional-grade grout results with less effort, the MudMixer is the tool that makes it possible. With its electric drivetrain, water control, and smart design, it’s changing the way pros and DIYers mix grout, mortar, and more.