How Thick Should Grout Be? What professionals say

If you’ve ever done a DIY project at home or worked in a professional construction setting, you probably have dealt with or heard about grout. People use grout to connect the spaces between tiles and other cracks or voids in building materials. Knowing how thick grout should be is essential to the application process, so it goes smoothly.

When applied, the thickness of the grout will depend on the project’s needs and can vary. Grout has to be mixed before use and should be smooth and malleable. It also shouldn’t be too thin or too thick and should be carefully applied with detail. 

It’s also crucial to learn how to apply the grout after it has been mixed correctly, and its thickness should be considered in different scenarios. Grout may also have other questionable qualities like shrinkage, length of drying times, etc. Keep reading to learn more about grout, how thick it should be, and how to properly apply it.

Understanding the Thickness of Grout During Mixing

When mixing grout, it’s important to understand its components. Grout is usually a mixture of sand, water, and cement. This mixture then seals joints and spaces between building materials like cement, tile, rock, and sometimes even wood.

Grout thickness when mixing depends upon the location of the grout and the project for which the grout is used. A general consensus agrees that grout is ready to slake, or rest, after reaching a “peanut butter” consistency. The grout will then chemically combine into the correct consistency for the job during the resting period.

● How Thick Should I Make My Grout?

The thickness of grout will depend primarily on the placement of the project. If the project you’re working on is on the floor, then the thickness of the grout can be a little runnier and spread out more. 

Grout on a wall should be thick enough to help support the materials to be held onto the surface. When mixing the grout, it’s important to first achieve a peanut butter-like consistency. After you’ve reached that level of thickness, you can further thicken or thin it out as needed for your project.

The Three Types of Grout

Three different common types of grout are used frequently. Each type has its own use, thickness, and drying properties. Grout is sometimes sold as a premixed compound but is more commonly found in a powdered form. Grout can be found in three common types: 

  • Sanded
  • Unsanded
  • Epoxy

Let’s look at each of these types in the following sections.

● Sanded Grout

Sanded grout is used for projects that require at least a 1/8-inch (3.2 mm) seam. This type of grout has a grainy-like texture and can damage other surfaces. Sanded grout is commonly used for tile flooring projects and can fill joints up to a ½-inch (12.7 mm) thick with a nice firm finish. It retains its size while drying, unlike other types of grout which may shrink.

● Unsanded Grout

Unsanded grout can also be used for flooring projects but is for smaller lines from 1/16th to 1/8th of an inch (1.6 to 3.2 mm). Unsanded grout contains finer, grit-free particles and is easier to work with around polished tiles and stones because it doesn’t damage the surrounding surfaces. It is common for unsanded grout to shrink while drying.

● Epoxy Grout

Epoxy grout differs from others because it contains different fillers like resins or silica. This type of grout is fine, can be used in delicate line work in the joints between tiles, and is best at 1/8th inch (1.6 mm). It should be noted that epoxy grout can be more difficult to use because it dries faster than normal sanded or unsanded grout.

What Happens if Grout Is Too Thick?

Sometimes grout is not mixed correctly or applied too thickly to the joints of the project. Grout that has not been mixed well can be dry or powdery from the get-go. Using grout that was prepared wrong and is too thick can also lead to problems.

If grout is too thick, it won’t do the job correctly and may crumble, crack, or otherwise fall apart at the seams of the project. Grout won’t fully seal the tiles if it’s too thick and can lead to water damage or tile breakage down the road.

Grout should be carefully prepared according to package instructions or according to the needs of the project. You should also spread it evenly, not getting it too thick or thin, to avoid future problems.

Does Grout Shrink When Drying?

Certain types of grout can shrink while drying, though not all will. This fact should be carefully considered when choosing the type of grout for the project. Grout can also develop bubbles and gaps if not applied correctly, so always take your time when applying it to any surface.

How Long Should Grout Sit Before Wiping?

Grout is usually applied quite generously over the lines, spaces, joints, and crevices where it is used. There is a waiting period for grout to settle into the lines and to begin drying and curing. Experts agree that 15 to 30 minutes is the ideal resting time before cleaning off the excess grout and the surrounding areas.

Can I Grout Over Grout?

In some projects, grout may already be between tiles or crevices. Old grout should be removed before new grout is used. Putting new grout over old grout isn’t advised because of faulty placement, sealant problems, bubbles, gaps, and overall failure to support the project. Remove old grout and replace it with the new grout to avoid these pitfalls.


If you have to work with grout in your next DIY project, it could be essential to know how thick it should be. If you’re mixing grout, the end result should look and feel like smooth peanut butter. 

Applications vary upon the project and can have thickness variations of 1/16th, 1/8th, and ½ an inch. There are three common types of grout: sanded, unsanded, and epoxy, and they have different uses for different materials.

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