2016 CBC Appendix I

[Inlander]

Has anyone had a deck cover denied due to the restrictions of CBC or IBC Appendix I? It states that a patio cover may be built with lighter live load (10 psi) and with some other light duty building requirements. Because of the way it's written, it seems that the intention is to allow people to built low cost light duty patio covers. The restrictions make sense (12' max, one story max). But I don't think the authors meant to disallow any roof covering an open space. Iv'e designed a free standing deck adjacent to a steel building with a roof above. The structure is designed with heavy duty steel columns, heavy timber beams and typical roof framing. This thing is designed per the building design requirements (not per Appendix I). But the plan checker is stuck on the idea that it is a "patio cover". My client is needs the cover. My position is that it is not a patio cover as described by the appendix.

Any opinions or useful feedback would be much appreciated.

 

[BAretired]

10 psi is not a light live load (I think you mean 10 psf).

Your design is rejected because the Plan Checker claims you should design for a lighter load? That seems a little bizarre. Maybe you should speak to his supervisor.

BA

 

[Inlander]

No, I don't think he wants it to be designed for a lighter load. He's just hung up on the statement that a patio cover shall not be higher than 12', nor be above one story. But I believe they mean patio cover as described in the context of appendix I (designed as an exception to normal structures). It's like saying you can build a barn with all the agriculture building exceptions, but you can't live in it. Then saying a house built to look like a barn can't be lived in. It seems so obvious to me. I was just wondering if I might be prejudiced because I really need to make this thing happen.

I spoke to his supervisor. He seemed to agree with me. But they had a meeting and decided to apply the statement to any roof that covers a patio or deck.

Nearly every custom home I design has a covered upper deck. I've designed 18' high patio covers. They're pretty common.

Thanks for your response.

 

[BAretired]

I don't understand the reason for limiting the height to 12' simply because the roof covers a patio. It seems to me to be an arbitrary requirement.

BA

 

[Inlander]

I guess the construction is inferior, but allowed for a rinky dink patio cover.

 

[GC_Hopi]

Sounds like you have a tough and unfortunate situation. Is this project in the states? Will you be sealing the project? You might have to reason with them that you are designing beyond the Appendix and are meeting the code not just the appendix. And by sealing you are taking on that responsibility.

 

[Inlander]

It's in Southern CA (Riverside County). That's exactly my position at this time GC Hopi. Thanks for the feedback.

 

[azcats]

How annoying. Clearly not the intent of the code.

Is this a residence or commercial building? I know it's not officially adopted yet, but the 2019 IBC has some verbiage in the 'user notes' stating that Appendix I only applies to patio covers accessory to dwelling units. It shows the intent that the appendix isn't intended to apply to structures that are designed in accordance with the balance of the code.

 

[chris3eb]

Are there some nonstructural differences between a "patio cover" and a "general structure"? I'm thinking of potential differences in plan check fees, permitting, property tax, zoning, ADA, seismic upgrades, egress, etc. It could be that whatever process you are going through requires a "patio cover" which meets the requirements of Appendix I, and there is a more involved process required for a "general structure".

 

[Inlander]

Azcats,

I'll definitely point out the new code user notes to the plan checker. Thanks.

chri3eb,

We're submitting for an ADU (accessory dwelling unit). So we're going through the whole CBC process with calculations, etc. The full 20 psf roof load is being used. I think the restrictions in Appendix I are just poorly written.

 

[chris3eb]

Inlander -
I understand that you are using 20psf and going through the CBC design process. Are you sure that the issue the AHJ has is structural though? There's a possibility that they have some other reason to limit the height to 12 feet and just aren't clearly explaining the reason to you. Maybe zoning in that area doesn't allow patio covers taller than 12 feet regardless of the design. Or maybe the ADU permitting process has limitations on the types of structures that can be added.

You may be completely right that the plan checker is simply misapplying this code requirement, but since you seem to have a brick wall, it may be a good idea to consider other possibilities.

Even if these other things aren't really an issue, bringing them up as potential issues may be beneficial in that it gives the plan checker an opportunity to go back on what they said earlier without admitting they were wrong. If you send a followup email reiterating that structurally it's ok and asking if it's a zoning/permitting/etc issue, you may be a form away from approval.