Precision and Performance from the Ground Up
At A Glance
• Dead-flat subgrade ensures long-term slab stability
• Rigid Heat-Sheet® Heavy locks PEX securely in place
• No tape, no shifting — faster installs, cleaner layouts
• Proven for shops, garages, and barn slabs alike
• Smarter prep = stronger, more efficient performance
This article is Part 1 of our three-part Garage Workshop Case Study with RR Buildings, following a real-world Heat-Sheet® radiant slab installation from prep to pour.
If you missed our introductory post on the performance benefits of Heat-Sheet® in radiant slabs, read it here.
The Project Context
Every high-performance radiant slab starts beneath the surface. For this build — a working shop that mirrors the needs of garages and agricultural barns — the RR Buildings team used Heat-Sheet® Heavy, a rigid, radiant-ready insulation panel engineered for strength, precision, and efficiency.
The goal: create a radiant-heated slab that can handle real-world abuse — vehicles, equipment, and temperature swings. Those same priorities apply whether you’re finishing a high-end hobby garage, a commercial workshop, or a livestock barn — the slab has to perform, season after season.
The Challenge
Conventional foam boards can crack or shift when driven over during a pour, especially in large, open spaces. Inconsistent subgrades and flexing panels lead to uneven concrete thickness and variable heat performance — two issues that compromise both durability and radiant efficiency.
The Heat-Sheet® Solution
Using a laser-set gravel base and lightweight aluminum rails, the RR Buildings crew achieved a subgrade so flat it looked machine-finished. Onto that surface, Heat-Sheet® Heavy panels interlocked cleanly and stayed rigid — no flexing, no gaps, no tape.
The nodules provided positive lock-in points for the upcoming PEX tubing, simplifying layout while protecting lines from shifting.
At the manifold wall, Halo® Subterra® Plus transitions created a flat, durable surface for routing and organizing the radiant tubing before it tied into the Heat-Sheet® Heavy field — a small but critical detail for a clean, efficient install. Unlike noduled panels, Subterra® Plus provides a smooth face that makes it easy to fan out, label, and staple the 32 supply and return lines with precision. Acting as both insulation and a layout platform, it bridges the transition between wall and slab seamlessly, keeping the manifold zone organized, the tubing protected, and the overall system performing at its best.
The Result
The finished base was flatter, faster, and stronger than traditional foam methods — the ideal platform for buggying in concrete on pour day.
The same qualities that made it perfect for this shop also make Heat-Sheet® Heavy ideal for garages and barns that demand durability, radiant performance, and long-term stability.
Wrapping It Up
Every radiant slab depends on what’s beneath it. With Heat-Sheet® Heavy, builders like RR Buildings get a system that installs cleanly, supports heavy use, and locks in radiant comfort — whether under a pickup, a workbench, or a tractor.
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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.
NEXT UP: Part 2 of our Garage Workshop Case Study with RR Buildings, where we dive into the panel layout and PEX installation process.
