Gypsum Concrete

Benefits of Radiant Floor Heating

  • Radiant heating systems supply heat directly to the floor
  • Uniform heat transfer, and superior crack-free thermal mass
  • Radiant heat transfer delivers heat directly to the people and objects in the room
  • It is more efficient than most electrical systems
  • Radiant systems can be advantageous to people with severe allergies
  • Costs less to run than forced-air heating because no energy is lost through ducts
  • Liquid-based radiant floor systems use little electricity
  • Energy-efficient and cost-effective



The Perfect Choice

FIRM-FILL® Gypsum Concrete is a cement-based floor underlayment designed for use in multi-family housing to satisfy acoustical ratings and fire codes, making it the perfect choice for new construction and renovation projects alike. K-Wall is certified to install this and other Hacker Floor Underlayments like FirmFill 2010® and FirmFill High Strength®, so whatever your needs, we have the products and resources for your project.


Energy-Efficient and Cost-Effective

GYP-SPAN® Radiant is a gypsum concrete floor product specifically designed for use with radiant heating systems. It is ideal when used over radiant heating tubes for uniform heat transfer, and forms a superior crack-free thermal mass. It encases the tubes or cables without air bubbles, creating a superior thermal mass that provides uniform heat transfer. GYP-SPAN® Radiant floor underlayment is the energy-efficient and cost-effective way to create a smooth, flat, evenly heated floor surface for the attachment of virtually any finished floor covering.


Radiant heating systems supply heat directly to the floor. Radiant heating is the effect you notice when you can feel the warmth of a hot stovetop element from across the room. Radiant heat transfer delivers heat directly to the people and objects in the room, not just by warming the air in a room like a heat pump. Liquid-based radiant floor systems use little electricity, a benefit for homes off the power grid or in areas with high electricity prices. Radiant floor heating has numerous advantages: it is more efficient than most electrical systems like baseboard heating and usually costs less to run than forced-air heating because no energy is lost through ducts. Because radiant systems do not use forced air, they can also be advantageous to people with severe allergies. The hydronic systems offer flexibility in that they can be heated with a wide variety of energy sources, including standard gas or oil-fired boilers, wood-fired boilers, solar water heaters, or some combination of these heat sources.

K-Wall Poured Walls is a licensed applicator of Hacker Industries Firm-Fill gypsum concrete products. Gypsum concrete is used in many applications in the building industry. We pour FirmFill products in mixed use, multi-family and hotel projects on sub-floors to provide the required fire and sound control required for safety and building codes. It is a self leveling mixture of FirmFill gypsum concrete, sand and water. Once poured it can be walked on in 90 minutes allowing work to resume quickly. For residential applications we most commonly pour Gyp-Span Radiant for in-floor heating systems. Gyp-Span Radiant is by far the smartest choice when in-floor radiant heat is installed. It is the most energy efficient thermal mass and does a excellent job of storing heat (energy) and distributing it evenly throughout your home. It turns your entire floor surface into a massive heat storing battery. Additionally you get the added safety benefit of a one hour fire rated floor, better sound eliminating qualities and the fact that it makes wood sub-floors more solid and helps eliminate squeaks.

The Process:
1) Prior to our arrival all sub-floors must be broom cleaned to the customers satisfaction, all plumbing holes and penetrations through sub-floor must be plugged and or fire caulked and bulk-heads in place where gypsum is not going to be poured.
2) A water supply of at least 15 gallons per minute with a hose bib connection must be within 100’ of the building. A dumpster to throw out empty bags must also be provided.
3) Pour crew arrives with required number of 80 pound bags of gypsum concrete, gyp pump, skid steer and tools to pour the floor.
4) Sand is delivered to the site.
5) Bonding agent is applied to the sub-floor
6) Gypsum, sand and water are put into the pump and thoroughly mixed then pumped into the building where the finish crew pours it to the correct depth and then back floats the surface to finish it.
7) 1.5 to 2.5 hours later the floor can handle light foot traffic.
8) Building temperature of 50 degrees or more & proper ventilation must be maintained a minimum of 5-7 days after the gypsum concrete is poured.


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Fletcher, NC 28732
(across from 145 Cane Creek Industrial Park)
Michigan Office: 231.943.4727
3773 Rennie School Road
Traverse City, MI 49685