Premium self-leveling underlayment

SpecFlow is a cement-based, self-leveling floor underlayment designed for interior applications. This high-quality, non-shrinking product ensures a smooth subfloor that is feather-edged compatible, preparing surfaces for carpet, tile adhesives, and other finishes. Simple to use, SpecFlow requires only mixing with water to achieve a smooth, flat, and hard surface.

  • SpecFlow produces a flowable underlayment with a flow time of 20 minutes at 70°F, requiring no troweling and enabling easy application.
  • It can be featheredged, offering flexibility in application thickness from a feather edge up to 2 inches, and up to 5 inches with pea gravel extension.
  • The product creates a smooth, blemish-free surface, eliminating the need for grinding or sanding.
  • It’s compatible with a variety of flooring adhesives, making it suitable for subsequent floor covering installations.

Tech Sheet
Safety Sheet


Application Instructions:

  • Surface Preparation: Follow ACI guidelines, ensuring the substrate is clean and profiled to a minimum CSP#3. Shot blasting is preferred for optimal surface preparation.
  • Priming: Use SpecPrime for priming, applying with a brush or broom to achieve 100 – 150 sq. ft. per gallon coverage. Porous surfaces may require a second primer coat.
  • Mixing: Combine 4 quarts of water with a 50-pound bag of SpecFlow, mixing for 2 to 3 minutes until smooth. For pump applications, adjust mixing time accordingly. The product allows for extension with pea gravel for thicker applications.
  • Installation: Apply SpecFlow over the prepped and primed substrate, using a long-handled spreader for distribution. The product is self-leveling and also suitable for pump application.


Available in 50 lb. bags, with coverage approximately 24 sq.-ft. at 1/4 inch thickness.

Shelf Life

SpecFlow offers a 12-month shelf life when stored properly in a cool, dry location.

Test Data

  • Set Time: SpecFlow has an initial set time of 50 minutes and a final set time of 80 minutes at 70°F.
  • Compressive Strength: It achieves 3000 psi in 1 day, with strength increasing to 5500 psi by 28 days.
  • Bond Strength: After 14 days with SpecPrime, it exhibits a bond strength of 1000 psi.
  • Flexural Strength: At 28 days, it achieves a flexural strength of 1150 psi.
  • Yield/Density: Each bag yields .50 cubic feet, with a density of 125 pounds per cubic foot.