Superior Strengthening Retrofit

The superior profile and manufacturing process of the TopHat Subframe Roof Retrofit Framing System is what sets it apart from competing systems such as RoofHugger. Read below to find out why.

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Short answer

What is the TopHat Subframe?

The TopHat Subframe is a hat-section retrofit purlin (a “top hat” purlin) for putting a new metal roof over an old metal roof. It is punched to fit the existing panel (R-Panel, UltraDek, 7.2 Rib, 7.0 Rib, standing seam and others), sits over the old roof, and is fastened along each existing purlin; the new roof attaches to it. Because it is fastened along the purlin, it also braces it: independent AISI base tests measured higher uplift and gravity capacity.

  • 3-1/2" height
  • 16 ga standard, 14 ga for high-load zones
  • 50 ksi steel, G90 galvanized
  • Patented (US 7,861,480)
  • Made in the USA

Superior Strengthening Metal Roof Retrofit

Diagram: TopHat Subframe fastened over the old metal roof panel, aligned with the existing purlin below

The TopHat Subframe is the industry's most advanced retrofit framing system. Featuring superior energy efficiency, a stronger structural profile and superior compliance with newly strengthened building codes, TopHat is the unchallenged leader in retrofit metal roofing solutions. The TopHat Subframe is compatible with a variety of standing seam and exposed fastener panels to complete your new roof.

The TopHat Subframe is an economical and efficient way to replace an existing metal roof. By putting a new and improved roof right over your existing roof structure, you achieve lower labor costs and minimal business interruption. The TopHat Subframe member is attached directly to the existing purlin (or to the deflection limiter between existing purlins). Your new roof panel is then attached directly to the TopHat Subframe.

Seamless Subframes

One of the many benefits of the roll-forming process used to manufacture the TopHat Subframe is that it can be produced in arbitrary lengths. Continuous subframe sections can go bay to bay or longer without splices creating a stronger roof than older systems that require splicing. In fact, in an early test of continuous TopHat Subframe, a test piece made from lower-strength steel still carried 7% more uplift than Roof Hugger™. The strength comes from the hat shape and continuous lengths. Today's standard TopHat is made from 50 ksi steel.

Stronger, Consistent Steel

The roll-forming process is superior when it comes to manufacturing consistency and tolerances with higher yield steels. It is generally accepted that roll forming produces an end product free from distortion due to springback. As a result, every single piece of TopHat Subframe is exactly the same, exactly as designed, and exactly what you want. In fact, roll-forming is the only way to manufacture the TopHat profile! Standard TopHat Subframe is 16 ga steel with a 50 ksi minimum yield and G90 galvanizing (ASTM A653), with 14 ga available for high-load zones.

Roof Hugger Compared to TopHat Subframe

Wind uplift structural improvement chart: baseline 0.382, Roof Hugger 0.740, TopHat 0.920 Gravity load structural improvement chart: baseline 0.811, Roof Hugger 1.450, TopHat 1.672
TopHat Subframe is significantly stronger than Roof Hugger in both Wind Uplift and Gravity Load testing