Florida Product Approval, or not

[scottiesei]

I am faced with a situation where non-approved hollow metal frames were used in a building. The frames are of sufficient strength to meet to required wind loads. Can I provide calculations justifying this for the project and be in compliance with the code? When I read the code, it seems that any "window" shall be tested. When I read the law, it sounds like we can hand calc if we need to. Has anyone faced dealt with something like this?

 

[Ron]

scottiesei....to some degree it depends on where you are located and particularly where your project is located. If it is in a windborne debris area, you have to have a Notice of Acceptance (NOA) on the windows/doors. If not within a windborne debris area, you might entice the local building official into accepting calculations, but keep in mind that the detail of the calculations will likely have to be similar to those submitted for an NOA. The FBC is clear on windborne debris areas (at least they made it a bit clearer in 2004/2005 revisions), but not necessarily so in other areas.

Window manufacturers are beginning to understand that they are the primary problem when they don't have NOA testing done.

Also, be careful with window labeling from the manufacturer. It is not always clear that the windows provided for a project are responsive to the site specific wind loads. Check AAMA 101S and make sure you are getting what you want out of the window manufacturers. The big discrepancy comes when, for example, a site has a design wind pressure of say 45 psf at the window, and the supplier submits a tested window rated heavy commercial 35 psf. Well, the window got tested to 35x1.5, so it has been tested past the design wind load; however, the standard (AAMA) says that the window must be tested to 1.5 x the design wind load, so it should be tested to 45x1.5.....the manufacturers will try to get this squeezed through every time! (Note...usually they do this not because it won't handle the structural loading, but won't handle the water intrusion test which then must be done at the higher pressure!)

Sorry for the diatribe....good luck.

 

[scottiesei]

Thank you for your reply Ron. The project is in Central Florida no WBDR here! I am going to get a hold of the building department and see what they say. The windows have no testing that I am aware of, I believe they came from the Carolina's. They are hollow metal frames, real heavy gauge. I am sure that I can get all of the mechanical properties and geometric sections. They are already installed and I was out there yesterday "testing" them with my hands and feet. They are not going anywhere. Also, they are relatively small, largest one being about 12 square feet. Also, there is another situation on the same project site in which they used windows with an expired NOA. To me, that should be relatively easy because I have the test data. I will just formulate new design eqs.

 

[Ron]

scottiesei....just because it is inland in Central Florida doesn't mean you're not in a WBDR. Under the Florida Building Code, ANY area where the wind speed is 120 mph or greater is a wind borne debris region. In Central Florida you have a few areas that are WBDR.... a large area of Orange County, Osceola County, all of Seminole County and others that are 120 mph or greater.

And keep in mind that you cannot put nearly enough load on a window with your hands and feet to adequately test it. For example, you 12sf window at 45 psf would carry a load of 540 lbs....not something you can press on and adequately assess. Another issue you need to check is the amount of gap between the rough opening and the window frame. If you are using nailing fins, it's not a big deal, but if you're using framed windows with no nailing fin, the gap makes a big difference in the fastener design. The fastener is then in bending and shear, thus the capacity goes way, way down!

 

[scottiesei]

Thanks again Ron, the project is located within the 110 mph so WBD is not an issue. The window is actually held by Z-clips welded to the frame. The Z-clips are then fastened with Teks to the structure. The windows are only about 3'-0" wide and the pressure is 35 psf. So assuming a trib of 1'-6" I am looking at about 52.5 plf. While I realize assaulting the frame is not an accurate method, I'm a pretty strong guy and did not see any deflection as I yanked. From what I understand, they have some testing for the different components, just not Florida approved for the whole assembly. If I am to do hand calcs, I am well aware that I will be responsible for transmitting the design load to the structure checking all of the failure modes of the different components.

 

[UcfSE]

The best thing to do is to call the building department and get instructions. Whether the windows are strong enough or not may be irrelevant if they find out they didn't get approval and therefore did not pay all the proper fees and such. It isn't worth getting your own part in a sling because of someone else's negligence.

 

[concretemasonry]

It may not be structural situation.

Perhaps there is a requirement for the glazing that does not apply only to hurricanes, but for most wind/debris concerns where you could get an occasional tornado.

These tests are done in a laboratory on complete window assemblies and on components.