At A Glance
- Plasticizer mix protects radiant tubing integrity
- Heat-Sheet® Heavy panels stay rigid under buggy traffic
- Accurate yardage planning prevents mix inconsistencies
- Smart details: door troughs, floor drains, control joints
- Built for real working buildings — shops, garages, and barns
This article is Part 3 of our three-part Garage Workshop Case Study with RR Buildings, following a real-world Heat-Sheet® radiant slab installation from base preparation through the final concrete pour.
If you missed our introductory post on the performance benefits of Heat-Sheet® in radiant slabs, read it here. You can also catch up on Part 1: Preparing the Base for Radiant Performance and Part 2: Smart Radiant Design for Shops, Barns, and Garages before diving into the final step of the installation.
Pour day is where all the preparation pays off.
With Heat-Sheet panels installed and PEX tubing snapped securely into place, the crew was ready to place the concrete slab that would power the building’s radiant heating system.
Because the building structure was already underway, the concrete couldn’t be pumped directly into the shop. Instead, crews moved it inside using concrete buggies — putting the slab prep and panel system to a real-world test.
Project Overview
The slab was designed for a high-use workshop environment similar to many garages, shops, and barns.
It needed to provide:
- Durable structural support
- Even radiant heat distribution
- Protection for PEX tubing during placement
- Consistent slab thickness across the building
The Challenge
Radiant slab pours introduce a few extra considerations.
Traditional foam boards can shift under foot traffic, reinforcing mesh, or buggy loads during placement, potentially affecting tubing position or slab elevation. Concrete mix design also becomes more important when pouring over insulation.
In a typical slab-on-grade pour, excess water in the mix can drain into the gravel base below. But when concrete is placed over insulation panels, that water has nowhere to go. Instead, it rises to the surface, which can weaken the finish and create curing issues.
To maintain workability without adding excess water, the crew used a plasticizer admixture. This allowed the concrete to flow and consolidate properly while preserving the strength of the mix — an important step when pouring radiant slabs over insulation.
The Heat-Sheet Advantage
As the pour progressed, one detail stood out immediately: the Heat-Sheet panels stayed completely stable. Even with buggy traffic and crew movement across the floor, the interlocking panels remained rigid while the molded nodules kept the PEX tubing securely in place.
This stability allowed the finishing crew to focus on placing and finishing the slab efficiently.
Builder Details That Matter
A few thoughtful details were built into the slab design to improve long-term shop performance:
Garage Door Trough
A recessed trough at the door opening helps prevent wind-driven rain or snowmelt from entering the building.
Floor Drain Placement
The floor drain was laser-set with proper slope before the pour, ensuring the finishers could screed directly to the correct elevation.
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The Result
From the first buggy load to the final broom finish, the slab performed exactly as planned.
The Heat-Sheet panels remained locked in place, the tubing stayed protected beneath the reinforcing mesh, and the concrete finished cleanly across the entire floor.
The result is a durable, radiant-ready slab built to handle decades of work in a busy shop environment.
Wrapping Up
The Dream Shop pour demonstrated what happens when careful preparation meets a reliable system.
For builders installing radiant-heated slabs in shops, garages, and barns, Heat-Sheet® provides a stable, efficient foundation that helps ensure the final concrete pour goes smoothly — and the finished floor performs for years to come.
About the Builder
This project comes from RR Buildings, led by Kyle Stumpenhorst — known for elevating post-frame construction through precision, craftsmanship, and innovation. His Dream Shop build sets the benchmark for how modern shops, garages, and barns can combine strength with radiant-ready performance.
Every stage of this radiant slab install reflects Kyle’s builder mindset: do it right, or don’t do it at all. And Heat-Sheet® Heavy fits that philosophy perfectly.
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