CAUTION!! ⚠️
This is a Public Service Announcement
Have you been provided a document claiming that rooftop duct supports are “pre-engineered to comply with wind loading”? If so, DO NOT BE FOOLED!!!
Other manufacturers make false claims about the wind rating of their systems. Some even provide a blanket statement to their products…THIS IS FALSE!!!
Do not accept a marketing flyer as an engineering document
| It is impossible to provide a blanket wind rating to roof supports. There are just too many variables: |
- Risk factor
- Building category
- Building height
- Size of items being supported
- Mount height off the roof
- Weight
- Length of run
- Etc.
ENGINEERING REPORT
We had our engineer run calculations to test the claims of a concrete duct support manufacturer, and this is what we found:
For a 36” x 36” duct to resist the overturning moment due to lateral forces caused by wind on a 40’ tall building (Risk Category 2), with 48” support spacing mounted 24” above the roof surface.
EACH BASE WOULD HAVE TO WEIGH 380lbs!
Conclusion: Non-penetrating or Free-Standing supports WILL NOT WORK in most situations.
SOLUTION: Require an Engineered System for all roof mounted items.
An engineered system by Rooftop Support Systems, a Division of Eberl Iron Works.
Strategically located anchor points allow for roof penetrations to be minimized while still meeting the project requirements.
1 (888) 243-2669
