What Does R-Value Actually Mean for Garage Doors?
Understanding the Numbers Behind Garage Door Insulation
If you’ve been shopping for a new garage door, you’ve probably seen R-values like R-12 and R-16.
They sound technical — but understanding them can help you choose a door that actually performs, not just one with a bigger number.
🧊 What Is R-Value?
R-value measures how well a material resists heat flow.
A higher R-value means better insulation — in theory.
However, when it comes to garage doors, R-value usually refers to the panel’s foam core, not the entire door system.
The actual performance also depends on:
Weather seals and joint design
How tightly the door fits
The quality of materials and installation
That’s why a professionally installed, well-sealed R-16 door can outperform a cheap “R-18” import any day.
🔍 Real-World Comparison
| Door Type | Construction | Best For |
|---|---|---|
| Non-Insulated | Single-layer steel | Unheated or detached garages |
| R-12 (≈1-3/8″ thick) | Polyurethane insulation | Great balance of cost & comfort |
| R-16 (≈1-3/4″ thick) | High-pressure polyurethane foam | Best choice for attached garages & workshops |
The difference between R-16 and R-18 is roughly 1 % more insulation — barely noticeable in everyday use.
The real upgrade happens when you go from non-insulated to insulated, or from R-12 to R-16.
🧪 Tested and Proven Matters
Manufacturers like Garaga go through rigorous third-party testing to verify their R-ratings.
Some off-shore or no-name doors claim R-18 or higher — but often aren’t tested and use low-density foams that create gaps, bubbles, and poor long-term performance.
At Rockwood Garage Doors, we only carry trusted and tested products that deliver on their claims.
✅ The Rockwood Recommendation
For most Ontario homes:
R-12 → Perfect for detached garages or spaces not constantly heated
R-16 → Ideal for attached garages, workshops, or areas where comfort matters
Both options offer reliable performance, lower energy costs, and long-lasting quality — without overpaying for inflated numbers.
📍 Visit Us
Ready to choose a door that fits your home and budget?
📞 Call Rockwood Garage Doors or visit our Milton showroom at 85 Steeles Ave E.
We’ll help you select a door that’s proven, tested, and built to last.
