At least two coats, one to seal your substrate and the other to topcoat. This may vary depending on the absorbency of the substrate, the specific system being used (e.g., a flake floor), and your desired level of wear resistance. 

Bubbles in Sparkfloor are typically caused by outgassing, trapped moisture, improper mixing, or sudden temperature fluctuations. These trapped gases push upward through the liquid resin, resulting in bubbles, blisters, or pinholes as the coating cures.

The primary culprits behind this bubbling include:

• Outgassing: Concrete is a highly porous material filled with microscopic air pockets. As temperatures rise, the air or gas inside the slab expands and pushes upward. When an unsealed concrete slab outgasses, the air escapes through the freshly poured, breathable epoxy, creating bubbles. 
• Moisture Vapor Transmission (MVT): If your concrete slab has elevated moisture levels or lacks a proper vapor barrier, moisture beneath the floor will evaporate and push upward. The trapped water vapor causes bubbling or blistering beneath the hardened epoxy.
• Improper Mixing: Aggressive or fast mechanical mixing can whip excess air directly into the epoxy resin and hardener. If these tiny air pockets are not rolled out properly during application, they remain trapped in the curing epoxy. 
• Temperature and Humidity Swings: Applying epoxy during peak heat or in direct sunlight can cause the coating to cure too quickly, trapping air or gas before it has time to escape. Similarly, rapid drops in temperature during the curing process cause air in the concrete to contract, drawing air bubbles through the coating.
• Improper Preparation: Skipping the crucial step of priming or sealing the concrete leaves the pores open, creating a clear pathway for gas and moisture to migrate into the epoxy layer.

Broadcasting flakes is all about achieving an even, natural pattern while working within the wet window of your base coat. Follow these steps for best results:

• Time it right: Broadcast immediately after rolling out your Sparkfloor base coat while it is still wet and sticky (usually within a 15–20 minute window).

• Throw UP, not DOWN: Scoop a handful of flakes, throw them upward toward the ceiling, and let them rain down naturally onto the wet floor. Throwing directly at the ground causes clumps and heavy patches.

• Determine your coverage:

  • Light/Medium Broadcast (10%–50%): Toss flakes lightly in scattered, sweeping motions to let the base colour show through.

  • Full Broadcast (100%): Keep throwing flakes until the floor is completely covered and no wet coating is visible (“throwing to refusal”).

• Walk carefully: Wear spiked shoes so you can walk over the wet coating to reach every corner without leaving footprints.

• Scrape and topcoat: Once the epoxy cures completely (usually 12–24 hours), lightly scrape or sweep off excess flakes to smooth the texture, then apply a clear topcoat to seal everything in.

Cure times depend on the ambient temperature and humidity, but typical turnaround times are:

Light Foot Traffic: 24 hours after applying the final coat.

Heavy Foot Traffic & Moving Furniture: 48 hours.

Vehicle Traffic (Driving & Parking): 5 to 7 days.

Why wait 5 to 7 days before driving on it?
Even if the surface feels hard to the touch after 24–48 hours, full chemical cross-linking takes up to a week. Parking a vehicle early can cause hot tire pickup, where hot tires bond with and pull the uncured coating off the floor when you drive away.

Pro Tip: Lower temperatures or high humidity will slow down the curing process. Allow an extra day or two for vehicle traffic if applying during colder weather (below 15°C).