FIRM-FILL® High Strength

FIRM-FILL® High Strength floor underlayment is the economical solution to correct concrete problems. It resurfaces any cracked or damaged concrete to better than new, providing surface hardness from 2500 to over 3800 psi. From feather edge to 3-1/2 inches in thickness, FIRM-FILL® High Strength floor underlayment provides a durable, flat floor for virtually any finished floor covering.

Recommended For

Concrete Toppings & Self-Levelers

Cracked or damaged concrete, pre-cast concrete, & cast-in-place concrete.

Features & Benefits

  • Corrects cracked or damaged concrete, creating a new, flat surface
  • Can be installed from feather edge to 3-1/2 inches in thickness
  • FIRM-FILL® High Strength floor underlayment has compressive strengths from 2500 – 3800 psi
  • Rapid installation; up to 25,000 square feet installed per day
  • Quick drying; can be walked on in 90 minutes
  • Expert application; installed only by trained, Licensed Applicators
  • FIRM-FILL® High Strength floor underlayment has approvals from ICC-ES and HUD
  • Meets ASTM F2419, Standard Practice for the Installation of Thick Poured Gypsum Concrete Underlayments and the Preparation of the Surface to Receive Resilient Flooring

External Resources

Sweets ProductTAG

CAD Details

Product Resources

Key: Word   PDF   Web Page
Product Submittal
3-Part Specifications
Project References
Drying Conditions Flyer
Post-Pour Instructions
Guidelines for Finished Floor Coverings

Featured Application

NordHaus Luxury Apartments Minneapolis, Minnesota
Technical Data Properties ASTM
Weight 7.6 lbs/ft2 at 3/4″ (19 mm) C472M
Thickness 3/4″ (19mm) (minimum over wood) to 3 1/2″ (89mm); 1/2″ (13mm) (minimum over concrete)
Compressive Strength 3000-3700 psi C472M
Thermal Performance K-value of 2.8Btu/ft2·h·°F; R-value of 0.36 ft2·h·°F/Btu C177
Fire Hazard Classification Flamespread index 0; Fuel Contribution 0; Smoke Density 0 E84, E136
Patty Size 8 1/2″ (approx. 216mm) plus or minus 1/2″ (13mm) in diameter
Sand 1/8″ (3mm) or less washed plaster or masonry sand E11
UL Listing Listed in over 100 1, 2, 3 and 4 hour floor/ceiling assemblies