TopHat Subframe Product Data
Hat-section retrofit framing for metal-over-metal reroofs
The TopHat Subframe lets a new metal roof go directly over an existing metal roof. Each member is punched to fit the existing panel profile, fastened to the existing purlins, and carries the new roof panels while bracing the purlins it is attached to. This page is the web version of the TopHat Subframe datasheet (PDF).
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.
Application
The TopHat Subframe is an economical way to replace an existing metal roof. Installing the new roof over the existing structure keeps labor costs down and avoids tearing off the old roof, so the building stays in use. Each TopHat member attaches directly to an existing purlin, or to a Deflection Limiter between purlins where engineering calls for closer attachment. The new roof panels then fasten directly to the TopHat.
TopHat works with a wide range of standing seam and exposed-fastener panels for the new roof.
Specifications
| Steel | 16 ga galvanized steel, 50 ksi minimum yield, G90 coating. 14 ga available for high-load zones. |
|---|---|
| Steel standard | ASTM A653/A653M |
| Origin | Made in the USA: manufactured in Pennsylvania from domestically produced steel. Mill certificates on request. |
| Height | 3-1/2" |
| Lengths | Made to the length the job needs; 10' and 20' are standard. Splices are required; see the installation guide and standard details. |
| Punch-outs | Custom punched to the existing roof panel profile. Standard punch-outs fit R-Panel, UltraDek, 7.2 Rib, 7.0 Rib and a variety of standing seam panels. See standard details. |
| Warranty | A 20-year substrate warranty covering the galvanized material is available at no additional cost, issued per project on request. |
| Lead time | Popular sections ship from inventory; others typically in about three weeks. |
| Delivery | Delivered pricing anywhere in the US. International shipping quoted on request. |
Engineering
Every TopHat retrofit is engineered for the building's design loads. TopHat Framing Systems can provide an engineering and shop drawing package for your project on request. Always consult a professional engineer registered in the state of your project before starting work.
AISI base test summary
These tests measure how much the TopHat Subframe increases the bending strength of the purlins it is attached to, by bracing them laterally and torsionally. Tests were run by Force Engineering & Testing under the AISI base test method. Full reports are on the test results page.
| Test | Existing purlin | Purlin alone | With TopHat |
|---|---|---|---|
| Wind uplift (R) | 16 ga | 0.382 | 0.920 (+141%) |
| Gravity (A) | 16 ga | 0.811 | 1.672 (+106%) |
| Gravity (A) | 12 ga | 0.840 | 1.548 (+84%) |
- The moment reduction factor (R) sets the nominal flexural strength of a purlin in negative bending (uplift).
- The moment amplification factor (A) sets the nominal flexural strength of a purlin in positive bending (gravity).
- These are AISI base tests of purlin bracing, not ASTM E1592 panel uplift tests.
Documents
- TopHat Subframe datasheet (PDF)
- CSI specification, Section 13 34 21 (also as 05 46 00; Word and PDF downloads there)
- Standard details (PDF and DWG)
- Installation guide
TopHat is a trademark of TopHat Framing Systems, LLC. TopHat is a patented roof subframe system (US 7,861,480 B2).