[Stubits]

Ok, so I just got the attached plans back from my architect. She's never designed a deck before and is doing this for us as a favor, more than anything else.

So, does this work? Any major concerns or flaws?

Specifically, what do you think of how the pergola structure attaches to the deck? What sort of connector would you use? Would something like this work? BC-BCS Post Caps

Where she calls for a 6x10, can I simply combine 4 2x10? Do they make a joist hanger large enough to support a 6x10?

My biggest concern is with the footers. The frost depth here is 30", so I know I need to go at least that deep, but what diameter should sonotube should I use?

Thanks guys!

[ballengerb1]

You will need a permit for this job so start there before asking us to evaluate the design. Codes vary so much the building department gets first say. They will also tell you the correct size of the footing, post sits on top of the footing not inside the tube. Most large lumber yards and box store will carry that 6x10 hanger. Simpson Strong Tie HUC610 6x10 Heavy Duty Joist Hanger Concealed/Reverse Flange

[Stubits]

Thanks so much. Totally agree. This is just one part of a much larger project, everything will be permitted.

Unfortunately the authorities here are not as helpful as they are elsewhere. They fail plans without offering any guidance, or so most times even an explanation of why it failed. I guess this comes with the territory living in a larger city, so I am just trying to avoid as many errors as possible.

[ballengerb1]

What city are you in and have you tried to downlaod that city's building code?

[Stubits]

I am in Washington, DC. We follow the 2006 IRC. I've been referring to this document, which seems helpful, http://www.awc.org/Publications/DCA/DCA6/DCA6.pdf.

Unfortunately I cannot find anything about pergola to deck attachments.

I really just want to make sure this is headed in the right direction. I think the architect might be overbuilding with the 6x10s and was hoping for a second opinion, so to speak.

[ballengerb1]

Try page 6. http://www.awc.org/Publications/DCA/DCA6/DCA6.pdf

[Stubits]

Thanks. I read that and it was helpful. That said, the architect is calling for a 6x10 to support the pergola. I'd love to know if that is necessary or overkill, and if I could get away with 3 2x10s.

[ballengerb1]

I am not an engineer but think that size is mostly for looks. The entire idea of a pergola is for looks in many cases.

[Stubits]

Hmm, for sure, but in this instance the 6x10 actually runs under the deck, in line with the joists and the pergola posts attach to the 6x10 beam. In this instance the beam is entirely structural as it won't be seen under the deck. There are smaller, more decorative beams above.

[ballengerb1]

6x10 under the deck is not a pergola it's a floor joist and three 2x10 will not be as strong. This is where being an engineer or architect comes in handy. They stamp their drawings showing they know the codes and have engineered their design to fit. The decorative beams on top are the pergolas.