Mortar, grout, and concrete all start with cement, and that’s where most of the confusion comes from.
Every contractor has worked with at least one of these three materials. Most have worked with all three. But mortar, grout, and concrete are not interchangeable, and on a high-demand job, using the wrong one means bond failures, cracked joints, and rework.
This guide breaks down what separates them and when each one belongs on the job.
What Are These Three Materials?
All three materials share a cement base. That’s the source of most confusion. But beyond that common ingredient, their composition, consistency, and purpose diverge significantly.
| Material | Primary Use | Key Ingredients |
|---|---|---|
| Concrete | Structural slabs, foundations, walls | Cement, coarse aggregate, sand, water |
| Mortar | Bonding masonry units together | Portland cement, fine sand, water, lime |
| Grout | Filling joints and voids | Cement, water, sometimes fine sand |
Each one serves a distinct purpose. Using one where another belongs is one of the most common and avoidable mistakes on a job site.
What Is Mortar?
Composition of Mortar
Mortar is a mixture of cement, fine sand, water, and typically lime. The lime improves workability and flexibility. The composition of mortar makes it thick and paste-like, designed to grip surfaces and hold masonry units in place as it cures.
Portland cement is the standard binding agent in most mortar mixes. It provides compressive strength and weather resistance when cured properly.
Types of Mortar
High-volume masonry work typically runs on Type S or Type N. Know which one your spec calls for before the job starts.
| Mortar Type | Compressive Strength | Best Application |
|---|---|---|
| Type N | ~750 psi | Above-grade, general exterior applications |
| Type S Mortar | ~1,800 psi | Below-grade, exterior, brick, stone, heavy loads |
| Type M | ~2,500 psi | Foundations, retaining walls, maximum load conditions |
| Thinset Mortar | Varies | Tile bonding directly to substrate |
Type S mortar is one of the most common choices in the field. It handles exterior exposure well and bonds reliably to brick, block, and stone.
Thinset mortar (also called thin set) is a modified version formulated specifically for tile. It contains additives that improve adhesion to smooth substrates. It’s not interchangeable with standard mortar for tile work.
When to Use Mortar
- Laying brick, block, and natural stone in masonry construction
- Setting tile using thinset mortar
- Repointing existing mortar joints
- Acting as a masonry adhesive between masonry units
What Mortar Is NOT For
Mortar is not a joint filler for tile installations once the tile is set. That’s grout’s job. And mortar should never be used as a substitute for concrete in structural pours. It lacks the compressive strength and coarse aggregate needed for load-bearing applications.
What Is Grout?
How Grout Differs from Mortar
Grout is not a bonding agent. It does not hold masonry units together. Its job is to fill the joints and voids left after materials are already in place.
Compared to mortar, grout has a much thinner consistency. It’s formulated to flow into tight spaces and cure in place, locking out moisture and debris.
Types of Grout
Understanding the type of grout you need matters before the job starts.
| Grout Type | Joint Width | Best Application |
|---|---|---|
| Sanded Grout (Standard Grout) | > 1/8 inch | Floor tile, ceramic, wider masonry joints |
| Unsanded Grout | < 1/8 inch | Polished tile, natural stone, narrow joints |
| Epoxy Grout | Any | Wet environments, chemical exposure, commercial kitchens |
| Non-Shrink Grout | N/A | Structural void fill, anchor bolts, column bases, precast |
Unsanded grout is specifically formulated for narrow joints and polished surfaces like natural stone. The fine sand in standard grout can scratch softer tile faces, which is why the distinction matters.
Epoxy grout offers superior water resistance and stain resistance. It’s non-porous and won’t absorb moisture, making it the right call for commercial kitchens, showers, and other wet environments.
Non-shrink grout is entirely different. It’s used in structural applications, like filling voids in concrete block, anchoring equipment, and leveling base plates. It’s not a tile product.
When to Use Grout
- Filling joints in any tile installation after the tile is set
- Void-filling in masonry work and precast applications
- Anchoring and leveling structural elements
- Any application where a joint needs to be sealed against moisture or debris
Grout Consistency: Where Many Jobs Go Wrong
On commercial jobs, grout mixed too thick won’t penetrate joints. Mixed too thin, it shrinks and cracks as it cures. The problem compounds when you’re running multiple batches across a large crew. Small inconsistencies become visible defects across hundreds of linear feet of joint. Getting the right consistency, batch after batch, is where the equipment you use makes a direct difference in the quality of the finished joint.
The EZG Grout Hog and mixer line was developed because the equipment available to contractors in the field wasn’t up to the job; machines prone to clogging, inconsistent output, and breakdowns that held up entire crews. EZG built mixing equipment from the ground up to deliver consistent, reliable results on grout and mortar applications.
What Is Concrete?
How Concrete Differs
Concrete contains coarse aggregate, including gravel, crushed stone, or similar material, in addition to cement, sand, and water. That aggregate is what gives concrete its compressive strength and makes it suitable for structural applications.
Mortar and grout do not contain coarse aggregate. That’s not a flaw, it’s by design. You don’t want aggregate trying to flow into a 1/8-inch tile joint or sit between brick courses.
Common Applications
- Foundations, slabs, columns, and structural walls
- Precast and refractory elements
- Concrete block manufacturing
- Sidewalks, driveways, and flatwork
What Concrete Is NOT For
Concrete should not be used to fill tile joints, set tile, or bond brick and block. Its texture, aggregate content, and mix design are wrong for those applications. Using concrete where mortar is specified results in poor bonding, inconsistent mortar joints, and long-term adhesion failure.
A Note on Portland Cement
Portland cement is the base ingredient in concrete, mortar, and grout. All three start with it. The difference comes down to what else is in the mix and in what proportions. The Portland Cement Association maintains detailed resources on cement chemistry and mix design for those who want to go deeper on material specifications.
Side-by-Side Comparison
| Feature | Mortar | Grout | Concrete |
|---|---|---|---|
| Primary use | Bonding masonry units | Filling joints and voids | Structural pours |
| Contains coarse aggregate | No | No | Yes |
| Contains sand | Yes | Sometimes | Yes |
| Mix consistency | Thick paste | Fluid to semi-fluid | Stiff, workable |
| Used for tile installation | Yes (thinset) | Yes (joint filling) | No |
| Structural/load-bearing | Partial | No | Yes |
| Water and stain resistance | Low | Varies by type | Moderate |
Choosing the Right Material for Your Construction Project
Selecting the right material starts with knowing what the material needs to do.
Bonding brick, block, or stone? Use mortar. Match the type to your exposure conditions. Type S for exterior and below-grade, Type N for above-grade general use.
Setting tile? Use thinset mortar to bond the tile to the substrate, then fill joints with grout once the tile is cured.
Filling structural voids or anchoring equipment? Non-shrink grout is the right call. It fills without pulling away from the substrate as it cures.
Pouring a slab, footing, or wall? Concrete. No substitution.
Working on a renovation project with existing masonry? Match the mortar type and color to what’s already there. Repointing with a stronger mortar than the original can cause spalling.
Common Mistakes to Avoid
- Using concrete in place of mortar between brick or block courses
- Filling tile joints with mortar instead of grout (shrinks, cracks, wrong texture)
- Ignoring grout type relative to joint width – different textures and joint sizes require different types
- Mixing grout or mortar by hand or with undersized equipment on high-volume jobs
The Equipment Behind the Mix
Getting the material right is only the first part. How you mix it determines whether that material performs the way it should.
Inconsistent mixing produces inconsistent results. Air pockets, poor hydration, and batch-to-batch variation all affect how mortar bonds and how grout fills. On a large masonry construction job or any high-volume construction project, that inconsistency compounds fast.
EZG Manufacturing’s mixing equipment was built specifically for these conditions. The EZG Grout Hog was the company’s founding product, developed by CEO Damian Lang after years of working in the field with equipment that clogged and broke down. Every design decision in EZG’s mixer line came from real job site experience.
For high-demand operations, the EZG hydraulic mixer line handles the output requirements of larger masonry and precast operations without the mechanical failures that plague lighter-duty equipment.
EZG equipment is built from 3/8-inch steel drum construction and designed with clog-prevention systems developed through field testing and contractor feedback. It’s built to last, and it’s backed by a 100% satisfaction guarantee.
If you’re sourcing mixing equipment for mortar or grout applications, browse EZG’s full mixer lineup or contact the EZG team directly to find the right machine for your operation.
