Roof Hugger completes testing of Corru-Fit

Roof Hugger Corru-FitUnveiled last fall at METALCON, Roof Hugger’s new retrofit sub-purlin system named Corru-Fit completed rigorous and successful ASTM E-1592 testing to prove its wind uplift performance value in a Metal-over-Metal retrofit application.

Corru-FitThe Corru-Fit sub-purlin product is specifically designed for installation over the old sine wave shaped corrugated metal roofs.  These old roofs are notorious for inconsistent corrugation rib spacing and therefore it is very difficult to provide a standard factory-notched Hugger sub-purlin that must attach directly into the building’s purlins in the low corrugation to be structurally correct.  Other methods like installing a continuous hat section over the corrugations and securing with a long fastener just doesn’t cut it from a structural standpoint.  Especially when the new roof assembly has to meet building code changes in respect to high wind speeds.

The Corru-Fit sub-purlin assembly is comprised of two 16-gauge components and a structural fastener. First is the 16-gauge steel spacer that installs at varying roof corrugation intervals to satisfy design loads. The spacer also has two tabs to receive the second component, which is a continuous zee-shaped purlin. This component has factory-notched slots in its base flange, which permits the variable spacer placement. To secure the components to the existing purlins, a special ¼-14 self-drilling stand-off Concealor fastener by Triangle Fastener Corporation is used that has an enlarged 5/8-inch diameter pancake head with a #3 square drive recess.            

Corru-Fit accommodates existing corrugated panels with rib depths up to 1¼-inch and spacing of 2.5 inches, 2.67 inches, 2.75 inches or 4.2 inches. Once installed, the system results in an overall sub-purlin assembly height of 2-3/4 inches, which allows for up to 3 inches of fiberglass insulation for greater thermal resistance and energy savings.

The Corru-Fit Hugger accomplishes every issue related to re-roofing corrugated metal roofs.  To satisfy updated building code requirements, Corru-Fit assemblies can be engineered to incorporate standard sub-framing members at the building’s corner and edge zones. For the new metal roof installed atop the Corru-Fit they can be your choice, either through-fastened/screw-down or standing seam from whatever manufacturer you wish.

Nowadays, every metal construction contractor and design professional needs all of the help to keep the work flowing. metal-over-metal retrofit is and always has been a great opportunity when new construction is impacted by bad economic times.  Today, Roof Hugger, Inc. and the Corru-Fit product have just made retrofitting a little bit easier for you.

To learn more about Corru-Fit and Roof Hugger, Inc., visit or call 800-771-1711

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