Slurry Broadcast Epoxy Flooring Systems: What Contractors Need to Know
Slurry broadcast systems have been around for a long time for a reason. When a job needs more build than a thin-film coating can provide, along with a tougher, more textured surface, a slurry/broadcast system offers contractors another way to achieve it.
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The basic idea is simple: graded aggregate is mixed into the resin to create a slurry; the slurry is placed at a controlled thickness; and additional aggregate is broadcast onto the wet surface. What makes the difference in the field is everything around that process — the concrete profile, slab temperature, aggregate gradation, batch size, thickness, broadcast timing, and recoat window.
Those details are what separate a well-executed slurry installation from one that creates problems in the field.
What Is a Slurry Broadcast Epoxy Flooring System?
A slurry/broadcast epoxy flooring system is a higher-build resinous floor system that combines resin with graded aggregate to create a flowable slurry. The slurry is pulled to the required thickness, allowed to level, and then broadcast with additional aggregate while the surface is still wet.
The aggregate in the slurry and the aggregate used for the broadcast serve different functions. The slurry aggregate adds body and affects how the mix moves and levels. The broadcast aggregate becomes part of the surface, adding build and helping create the finished texture.
For contractors, that means aggregate is not just filler. The type, gradation, and shape matter.
Where Slurry Broadcast Systems Make Sense
A slurry broadcast system is worth considering when the project calls for more system build and more texture than a typical thin-film coating. It can be a practical choice for commercial and industrial floors where contractors need a more substantial resinous system and want control over the finished profile.
The exact build still has to match the job. Traffic, chemical exposure, substrate condition, service environment, and the texture the customer expects all matter. A slurry system is not automatically the right answer just because the floor is industrial.
It Starts with the Concrete
Slurry gives you more build, but it does not make poor concrete preparation disappear. The slab still has to be clean, sound, and properly profiled.
Proper surface preparation is critical to a successful slurry broadcast installation. The concrete should be clean, sound, and properly profiled for the specified resinous flooring system. Porous or uneven concrete can also affect material consumption and increase the risk of outgassing, so slab condition should be evaluated before the first batch is mixed.
Temperature Changes More Than Cure Time
Contractors know a cold floor slows things down. On a slurry job, temperature also changes how the material moves, spreads, and levels.
Do not rely on room temperature alone. Check the material, the air and the slab itself. A slab-on-grade floor can be noticeably cooler than the room, and that can change viscosity, coverage and working time.
Dew point belongs in that same check. As a general resinous-flooring practice, keep the substrate at least 5°F (3°C) above the measured dew point during application and initial cure to reduce the chance of condensation forming on the slab.
Slurry Sand Is Not Generic Sand
One of the easier mistakes to make is treating slurry aggregate as if it were interchangeable. It is not.
Particle size distribution and shape affect how the mix flows and self-levels. Change the aggregate, and you can change how the slurry behaves. Aggregate selection should match the resin system, application method, and finished profile the project requires.
| Thermal-Chem system example Thermal-Chem’s TC #4 Slurry Sand is mixed into the resin to create the slurry, while TC #6 Broadcast Sand is applied to the wet surface to build the finished profile and texture. |
Control the Build as You Go
A slurry floor should not be something the crew measures after it cures. Thickness needs to be controlled while the material is going down.
Use a screed rake or other depth-gauge device, keep checking the setting, and watch material usage as the placement moves across the floor. If the floor starts running heavy or light, it is better to catch it during the pour than at the end of the job.
Slurry broadcast aggregate adds additional build, approximately 1/8-inch slurry finishing at roughly 3/16 after broadcast, depending on the basecoat and job conditions, so contractors need to account for both the slurry thickness and the broadcast when planning the finished system.
Mix for the Crew, Not for the Mixer
Batch size needs to match what the crew can actually place, with a general placement window of approximately 25 to 30 minutes; however, rapid-cure materials will move faster. Mixing more material does not help if the placement side cannot keep up. Working time will vary by product and job conditions, so mixing, delivery, placement, leveling, and broadcast all need to stay together.
Broadcast Technique Shows Up in the Finished Floor
Once the slurry has had time to level and is still wet, the broadcast needs to go down evenly. Throwing the aggregate upward and allowing it to fall onto the surface gives a more uniform broadcast than driving it directly into the resin.
On larger placements, keep a wet edge so the next section ties in cleanly. That is a small field detail, but it can make a visible difference in consistency.
Know the Texture Before You Start
A slurry broadcast system can be finished with a heavier profile, a medium texture, or a smoother finish. Aggregate size, broadcast amount, sanding, and topcoat application all affect how the floor feels and looks when it is done.
The important part is deciding what you are trying to hit before installation. Trying to turn a heavily broadcast floor into a smooth one after the fact creates unnecessary work.
A Purpose-Built Slurry Option: #728 ArmorTred SL
For contractors who want a purpose-built epoxy slurry option rather than assembling a system from a compatible resin and separately selected aggregate, Thermal-Chem offers #728 ArmorTred SL
#728 ArmorTred SL is a three-part, aggregate-filled epoxy slurry system. The 100% solids epoxy can be installed as a thicker, self-leveling slurry when combined with selected Thermal-Chem aggregate, giving contractors a system specifically designed for this type of application.
#728 ArmorTred SL provides a durable, high-gloss surface with good impact, abrasion, and chemical resistance and is designed for interior applications. Depending on the specified system and texture, it can be used for applications such as industrial floors, warehouse floors and aisles, processing areas, food-preparation areas, walkways, and pedestrian or vehicular ramps.
For contractors, the advantage is straightforward: rather than selecting a resin and aggregate combination on their own, #728 ArmorTred SL provides a defined Thermal-Chem epoxy slurry option with specified components and its own mixing and installation requirements.
Contractor takeaway: #728 ArmorTred SL gives contractors a product-specific epoxy slurry option with defined components, application guidance, working time, coverage, and installation requirements. Review the #728 ArmorTred SL Technical Data Sheet before installation for complete product-specific details.
[DOWNLOAD THE #728 ARMORTRED SL TECHNICAL DATA SHEET]
A Few Things Worth Checking Before the First Slurry Broadcast Batch
- Are you using the general slurry broadcast method or a product-specific slurry system?
- Is the concrete profile where it needs to be?
- What are the slab, material, and ambient temperatures?
- Is the slab safely above dew point?
- Do you have the correct slurry and broadcast aggregate?
- Can the crew place the batch inside the available working time?
- Is the gauge rake set and being checked?
- Is the broadcast staged and the wet-edge plan clear?
- Is the topcoat onsite and is the recoat window understood?
Quick Contractor Questions
What is the difference between a slurry and a broadcast system?
A slurry mixes graded aggregate into the resin to create a higher-build material. A slurry broadcast system adds another aggregate application to the wet surface.
Why does aggregate gradation matter?
Because particle size and shape affect flow and self-leveling. Changing the sand can change the behavior of the mix.
How thick is a slurry broadcast floor?
It depends on the system. As a general guide, Thermal-Chem’s suggests approximately 1/8-inch slurry finishing at roughly 3/16” after broadcast.
How does aggregate selection affect a slurry broadcast system?
Aggregate selection affects how the slurry flows, builds, levels, and finishes. Particle size, gradation, and shape can also influence the texture and performance of the completed floor. Contractors should select the aggregate based on the specified system and the finished profile the project requires.
Need Help With a Slurry Broadcast Project?
For help selecting the right resin, aggregate, system build, or application approach for a specific project, contact Thermal-Chem’s technical team at 800-635-3773.
Thermal-Chem also offers manufacturer-direct product availability and same-day shipping on more than 90% of orders to help contractors keep projects moving.
