Why cure time, strength, surface prep, and jobsite conditions matter—and where LCB Rapid shines.

When it comes to choosing the right self-leveling underlayment (SLU), the decision often comes down to one critical factor: time. Installers and flooring contractors are constantly balancing tight schedules, substrate conditions, and performance requirements—and the choice between a rapid-set and a standard-set underlayment can make or break a project timeline.

Whether you’re resurfacing compromised substrates, correcting uneven floors, or prepping for moisture-sensitive finishes, understanding the differences between these systems is essential. Here’s what you need to know before you pour—and why SKIMFLOW® LCB RAPID is becoming the go-to solution for fast-track projects across the country.

1. Cure Time: The Biggest Difference in Real-World Productivity

The biggest advantage of rapid-set products is simple: they get you back on the floor faster.

SKIMFLOW® LCB RAPID is engineered specifically for compressed timelines:

• Foot traffic in as little as 90 minutes

• Flooring installation as soon as the next day

• 40% faster to foot traffic, 20% faster to flooring compared to standard-set options

On busy commercial jobs—or residential remodels where downtime means disruption—those hours matter. Less waiting means more progress, fewer return trips, and fewer scheduling conflicts with follow-on trades.

Standard underlayments work well for many projects, but when every minute counts? Rapid-set wins.

2. Strength & Performance: Rapid Doesn’t Mean Compromised

There’s a misconception that faster cures mean lower density or reduced durability. LCB Rapid proves otherwise.

LCB Rapid delivers a high-density, fiber-reinforced surface that stands up to heavy use, including:

• Superior resistance to wheel tracking

• Improved durability on distressed gypsum substrates

• A smooth, strong base for a wide range of floor finishes

The result is a surface that performs like a traditional SLU—but without the traditional wait times.

3. Substrate Versatility: Rapid Solutions That Adapt to the Job

Every jobsite is different, and substrate conditions rarely cooperate. The ability of a rapid-set underlayment to perform across a variety of bases is crucial.

LCB Rapid is designed for use over:

• Gypsum underlayments

• Approved wood subfloors

• Approved adhesive residue

• Compromised or damaged substrates

• Concrete

• UL Fire-Rated Assemblies

This versatility makes LCB Rapid a true problem-solver—ideal for remodels, multifamily work, office buildouts, tenant improvements, and any project where existing conditions vary.

4. Surface Prep Still Matters—Rapid or Not

Rapid-set doesn’t mean “skip prep.” Proper evaluation and preparation remain the foundation of any successful SLU installation.

Before choosing between rapid-set and standard underlayments, consider:

• Moisture levels and humidity

• Temperature and airflow

• Substrate stability and contamination

• Required thickness and coverage rates

• Follow-on trades and project sequencing

Even with a fast-setting formula, the substrate must be sound, clean, and primed appropriately to ensure full bond and long-term performance.

5. When to Choose Rapid-Set Underlayments

Rapid-set solutions like LCB Rapid are ideal when:

• You’re working on tight deadlines

• The space must reopen the same day or the next day

• You’re resurfacing damaged gypsum

• You need fast-track construction workflows

• The jobsite poses access or schedule constraints

• You want predictable performance in cold or variable conditions

If your schedule is flexible, a standard underlayment may still be the right fit—but rapid-set products offer unmatched value when time truly equals money.

The Bottom Line: LCB Rapid Delivers Speed Without Sacrificing Strength

SKIMFLOW® LCB RAPID gives installers the performance of a traditional self-leveling compound with a dramatically accelerated timeline.
It’s engineered for fast-track interiors, difficult substrates, and demanding commercial workloads—helping you keep projects moving without compromising quality.

When cure time, workflow, and jobsite conditions matter, rapid-set isn’t just an upgrade—it’s a competitive advantage.